Formula of square area
a = s²
thus, area of the first square could be written as s₁² and area of the second square could be written as s₂²
First, write an expression in the form of equation system
An expression for "The combined area of two squares is 45 square centimeters" is:
⇒ s₁² + s₂² = 45 (first equation)
An expression for "Each side of one square is twice as long as side of the other" is:
⇒ s₁ = 2s₂ (second equation)
Second, solve the equation system by substitution method.
⇒ We could substitute 2s₂ to s₁ (second equation) in the first equation in order to find the value of s₂
s₁² + s₂² = 45
(2s₂)² + s₂² = 45
(2²)(s₂)² + s₂² = 45
4s₂² + s₂² = 45
5s₂² = 45
s₂² = 45/5
s₂² = 9
s₂² = 3²
s₂ = 3
⇒ Substitute the value of s₂ to the second equation in order to find the value of s₁
s₁ = 2s₂
s₁ = 2(3)
s₁ = 6
The length of each side of the larger square is 6 centimeters