Question

tìm X, bt.

x (x+10)-x(x+2)=30            

Mong mn gúp vs ạ SOS

Answer 1

` <=> x^2 + 10x - x^2 -2x = 30 ` 

` <=> 10x - 2x = 30 ` 

` <=> 8x = 30 ` 

` => x = {30}/8 = {15}/4 ` 

Answer 2

\(x\left(x+10\right)-x\left(x+2\right)=30\\ x^2+10x-x^2-2x=30\\ 8x=30\\ x=3,75\)

Answer 3

\(x\left(x+10\right)-x\left(x+2\right)=30\)

\(\Rightarrow x\left(x+10-x-2\right)=30\)

\(\Rightarrow8x=30\Rightarrow x=\dfrac{15}{4}\)

Answer 4

`x(x+10)-x.(x+2)=30`

`x^2 + 10x - x^2 - 2x = 30`

`(x^2-x^2) + (10x-2x) = 30`

`8x = 30`

`x=30:8`

`x=15/4`

`x = 

Answer 5

`x(x+10) - x(x+2) = 30`

`<=> x^2 + 10x - x^2 + 2x = 30`

`<=> (x^2 - x^2) + (10x - 2x) = 30`

`<=> 8x = 30`

`<=>  x  = 30/8 = 15/4`