Question

Value of X?
7x+3x=90?

Answer 1

7x+3x=90
7x+x=90-3
7x+x=87
X^2=87-7
X^2=80
(Take the square root of both X^2 and 80)
*answer= 8.94 (round off to whole number =9)


(Proof check yourself)

Answer 2

10x=90
X=9

To check

7 (9) + 3 (9)
63+27
=90