3×+7.4=20 6.4×+3.6×=51

3×+7.4=20 6.4×+3.6×=51

3×+7.4=20
3x=20-7.4
3x=12.6
x=4.2
6.4×+3.6×=51
(6.4+3.6)x=51
10x=51
x=5.1

Solving the bivariate linear equation 4y-5x = 40,5.5x-8y = 420

4y-5x = 40 [Formula 1]
5.5x-8y = 420 [Formula 2]
The formula [1] × 2 + [2] gives - 4.5X = 500
Then x = - 1000 / 9
Y = - 1160 / 9 is calculated by [Formula 1]
That's all

1.5x minus 15x is 2 and 7 percent

1.5X-0.15X=2.7
1.35X=2.7
X=2

The three sides of a triangle are 5 √ 5 / x, 2 / 1 √ 20x, 4 / 5x √ 5x / 4
The Chinese translation is five times the root, five times the X, two times the 20x, four times the 5x, four times the 5x
Find its circumference (simplify the result)
② Please give an appropriate value of X so that its perimeter is an integer, and find out the value of the perimeter at this time

5 √ X of 5 = 1 of 2 √ 20x = 5x of 4 √ 4 of 5x = √ 5x
① Find its circumference
3√5X
② Please give an appropriate value of X so that its perimeter is an integer, and find out the value of the perimeter at this time
X=√5
In this case, the value of perimeter = 15