Question

Определите Корнями каких уравнений являются 3,4 и 7
1. 8(x - 1/2 ) + 5 ( x -3/5) = 4 ( x+ 5 )
2. 4(x-3)+ (3x-5) =32
3.5x-2=18x-41
4.15(x-2)==7x+2

Answer 1

Объяснение:

1)

$8(x - \frac{1}{2} ) + 5(x - \frac{3}{5} ) = 4(x + 5) \\ 8x - 4 + 5x - 3 = 4x + 20 \\ 13x - 4 - 3 = 4x + 20 \\ 13x - 7 = 4x + 20 \\ 13x - 4x = 20 + 7 \\ 9x = 20 + 7 \\ 9x = 27 \div 9 \\ x = 3$

2)

$4( x - 3) + (3x - 5) = 32 \\ 4x - 12 + 3x - 5 = 32 \\ 7x - 12 - 5 = 32 \\ 7x - 17 = 32 \\ 7x = 32 + 17 \\ 7x = 49 \div 7 \\ x = 7$

3)

$5x - 2 = 18x - 41 \\ 5x - 18x = - 41 + 2 \\ - 13x = - 41 + 2 \\ - 13x = - 39 \div - 16 \\ x = 3$

4)

$15(x - 2) = 7x + 2 \\ 15x - 30 = 7x + 2 \\ 15x - 7x = 2 + 30 \\ 8x = 2 + 30 \\ 8x = 32 \div 8 \\ x = 4$