Question

explain the steps from x+√x²-√9 to 3.75cm( the steps enclosed in a box)

Answer 1

x+ √x²-9 +√x²-9 +x =12

2x +2√x²-9 =12 [ here x+x =2x, and √x²-9 +√x²-9 = 2√x²-9]

divide each term with 2

x+√x²-9 = 6
sutract x both sides
√x²-9 = 6-x

square both sides
(√x²-9)² = (6-x)²

x² -9 = 6²+x²-2*6*x

x²-9 = 36 +x²-12x

subtract bothsides x²
-9 = 36-12x

-9-36 = -12x
-45 = -12x
-45/-12 =x
15/4 =x

therefore
x= 15/4
x= (15*25)/(4*25)
x= 375/100
x= 3.75