4.5y-2.5y = 17.5 how to solve the equation

4.5y-2.5y = 17.5 how to solve the equation

2y=17.5
y=17.5÷2
y=8.75

A simple algorithm for solving 143 * 7 + 375 * 333 + 250 math problems online

143*7+375*333+250
=1001+125*3*333+250
=1001+125*999+125*2
=1001+125*(999+2)
=1001+125*1001
=(125+1)*1001
=126*1001
=126126

If the first n terms of {an} and Sn = 3N + B, then B ()
A.3 B.0 C.-1 D.1

Sn=3n+b ①
S(n-1)=3(n-1)+b ②
The subtraction of the two formulas has an = 3;
So the general term of the equal ratio sequence {an} is
an=3；
So Sn = 3N;
So B = 0

Simple operation of 98 - (96 + 96 / 97) / 96

98 - (96 + 96 / 97) / 96
=98 - (96 / 96 + 96 / 97)
=1 / 98-1 / 97
=96 and 96 out of 97

As shown in the figure, in the parallelogram ABCD, AE ⊥ BC, AF ⊥ CD, the perpendicular feet are e, F, ∠ EAF = 60 °, CE = 1, CF = 4,
Find the length of each side of parallelogram ABCD

In the quadrilateral afce, ∠ C = 360 ° - 90 ° - 90 ° - 60 ° = 120 ° so ∠ B = ∠ d = 60 ° of the parallelogram. In the right triangle ABF and ade, ab = 2BF, ad = 2DE is the hypotenuse of the parallelogram AB = a, then BF = 0.5A, BC side length is 0.5A + 4de = cd-ce = A-1, ad = 2DE = 2 (A-1), parallelogram side ad = BC

Fill in the operation symbols and brackets in the following formula to make the equation hold
0.5（）0.5（）0.5（）0.5（）0.5=4
0.5（）0.5（）0.5（）0.5（）0.5=6
0.5（）0.5（）0.5（）0.5（）0.5=8

[(0.5+0.5)+(0.5+0.5)]/0.5=4
(0.5+0.5+0.5)/0.5/0.5=6
(0.5+0.5)/0.5/0.5/0.5=8

A 3 * 3 matrix with eigenvalues of 1, - 1,0. Prove that the cube of a = a, and the square of a is not equal to a

The square of eigenvalue is 1.01, and the cube of eigenvalue is 1.0 - 1, so we have got the proof. I don't believe you will add a few jumps in the middle... It's the same method as the 50 th power and 100 th power... When we only learned the second order, we used this kind of problem to prove

When he did an addition, he took the number 7 on the tenth digit of an addend as 6, and the number 3 on the third digit as 5. As a result, he got 42. What's the correct answer?

7 on the 10th is 70. So 10 is missing. 2.10 minus 2 = 8

Let the rank of matrix A = (AIJ) 4 * 3 = 2, and matrix B = [102,020, - 103], then the rank (AB)=

B=
1 0 2
0 2 0
-1 0 3
-->
1 0 2
0 2 0
0 0 5
So r (b) = 3
So B is reversible
So r (AB) = R (a) = 2

2 times of a number is less than 6 times of its 0.25 times. What's the number

0.25x-0.2x=6
0.05x=6
x=120