The error is in the second step they subtracted 3 from both sides but it was a 3x, which you can not do.
Correction.
9x+18+3x=1
12x+18=1
12x=-17
x=-17/12
Answer:
I think b, but I may be wrong
ANSWER
a) One Solution
b) the solution is x=2
EXPLANATION
The given equation is:

We expand to get;

Group similar terms;

This implies that,

Divide both sides by 10 to obtain,

Answer:
20
Step-by-step explanation:
Given :
Length = l
Width = w
Area of square = 45
Let side of square = x
Area of square = x²
45 = x²
√45 = x
l of rectangle = x + 5 = √45 + 5
w of rectangle = x -5 = √45 -5
Area of rectangle= l * w
Area = (√45 + 5) * (√45 - 5)
Area = 45 - 5√45 + 5√45 -25
Area = 45 -25
Area of rectangle = 20