8X^2-5x(4Y-X)+4X(-4x-5/2Y)=

8X^2-5x(4Y-X)+4X(-4x-5/2Y)=

8X^2-5x(4Y-X)+4X(-4x-5/2Y)=
=8x²-20xy+5x²-16x²-10xy
=-3x²-30xy
8X^2-5x(4Y-X)+4X(-4x-5/2Y)=8X^2-20XY+5X^2-16X^2-10XY
=(8X^2+5X^2-16X^2)+(-20XY-10XY)
=-3X^2-30Y
In known triangle ABC, a = 5, B = 3, angle c = 120 °, then Sina =?
A 14 / 5 root number 3, B 7 / 2 root number 3, C 14 / 3 root number 3, d 7 / 3 root number 3
Can we use area? But I can't do it
B
Choose a
c^2=a^2+b^2-2abcosC=25+9-2*5*3*(-1/2)=49
C=7
a/sinA=c/sinC
5/sinA=7/(√3/2)
sinA=(5/14)√3
B
This is the application of the sine theorem. I suggest you solve it by the theorem yourself. We tell you that the result is meaningless. Study hard and work hard for the University
Choose a
Make the vertical line of AC extension line through B and cross it to d
∵∠C =120°
∴∠CDB = 60°
In RT △ CDB, CD = 2.5, DB = 5 √ 3 / 2
In RT △ abd, AB & sup2; = ad & sup2; + DB & sup2;
∴AB = 7
∴sinA = DB/AB = 5√3/14
Calculate the following two questions: 1. (x + 4Y) (- x-4y) 2. (1 / 2x ^ 2 + 5Y ^ 2) ^ 2
1.（-x+4y)(-x-4y)
=(-x)^2-(4y)^2
=x^2-16y^2
2.(1/2x^2+5y^2)^2
=(1/4)x^4+5x^2y^2+25y^4
1.(-x+4y)(-x-4y)
=(-x)^2-16y^2
=x^2-16y^2
2.(1/2x^2+5y^2)^2
=(1/4)x^4+5x^2y^2+25y^4
Solve the equations 4x-6 {x} = 43 and [2x] = 4x-7
Integral problem equation
The smaller of four times x minus six times x is forty-three
The rounding of two X is four times x minus seven
The first equation is: 4x-6 {x} = 43. First, do not take a small estimate, x = - 21.5. Then take the number near - 21.5, {x} as an integer, then 4 times of the fractional part of X is an integer. We get x = - 20.75
The second equation is also estimated, and it is OK to get x = 3.5. However, it is not only this solution. 4x has to be an integer, and it is verified that 3.25 also meets the requirements, but it does not meet the requirements when it is small
Write the title clearly, I can't understand it
X is not small!!!!!!!!!!!!!!!!!!!!!!!!
Calculation of (2Y square-4y + 1) - (4Y square + 5y-3)
(2Y square-4y + 1) - (4Y square + 5y-3)
=2Y²—4Y+1—4Y²-5Y+3
=-2y²-9y+4
7.6 + 0.5-4x = 6
7.6+0.5-4x=6
8.1-4X=6
4X = 8.1-6 [this is a key step]
4X=5.1
X=0.525
8x+4y=2 6x+5y+7=0
8x+4y=2 6x+5y+7=0
4x+2y=1 （1）
6x+5y=-7 （2）
(2) * 2 - (1) * 3
4Y = - 17 is y = - 17 / 4
Substituting (1) (2) x = 19 / 8
So x = 19 / 8, y = - 17 / 4
4X - 6 = 3x + 5 to solve the equation
The transferred items are:
4x-3x=5+6
x=11
Hope to adopt
4x-6=3x+5
4x-3x=5+6
Thank you
{11x+4y=115 8x+5y=115
11x+4y=115 1）
8x+5y=115 2）
1) - 2)
3x-y=0
y=3x
Substituting 1), we get
11x+12x=115
23x=115
X=5
y=3x=15
1. If 2x_ Y = 4, then Y / 4x_ In the range of natural number, the solution of equation 3x + y = 10 is
In the range of natural number, the solution of equation 3x + y = 10 is
x=1, y = 7
x = 2, y = 4
x = 3, y = 1
1. 2x-y=4
2x-4=y
y/4x-8=y/2(2x-4)=y/2y=1/2
2. In the range of natural number, there are three solutions to the equation 3x + y = 10
x=1,y=7
x=2,y=4
x=3,y=1
2x-y = 4,3x + y = 10 to solve the quadratic equation of two variables: x = 2.8, y = 1.6. From the meaning of the problem, 4y-8 is not equal to 0, that is, y is not equal to 2, x = 2.8, y = 1.6
In the range of natural number, the solution of equation 3x + y = 10 is
x=1, y = 7
x = 2, y = 4
x = 3, y = 1
1. Because 2 divided by Y / 4 equals - 8, that is, 2 multiplied by 4 / y equals - 8, so the null is 1, y equals 1
When you bring y = 1 back
If 2 times 2Y equals 4, fill in 2
The correct order is 2.. One