Question

Solve the system by substitution.
y + 4 = x
10x + 2y = 16

Answer 1

x = 2 and y = -2

Explanation:

Given system :-

y + 4 = x

10x + 2y = 16

Solve the system by substitution:-

Let,

y + 4 = x ...(1)

10x + 2y = 16 ...(2)

Solve for y;

Substitute y + 4 as x in the eq.(2)

10( y + 4 ) + 2y = 16

• Distribute 10.

10y + 40 + 2y = 16

• Combine like terms.

12y + 40 = 16

• Move constant to the right-hand side and change their sign.

12y = 16 - 40

• Subtract 16 from -40.

12y = -24

• Divide both side by 12.

12y / 12 = -24/12

Hence, y = -2

Solve for x.

• Substitute the value of y in eq.(1)

-2 + 4 = x

• Add -2 and 4.

Hence, 2 = x

Answer 2

• (2, -2)

Explanation:

Given system:

• y + 4 = x
• 10x + 2y = 16

Substitute x into the second equation:

• 10(y + 4) + 2y = 16
• 10y + 40 + 2y = 16
• 12y = -24
• y = -2

Find x:

• x = -2 + 4
• x = 2