Question

Question 18 Solve simultaneously x + y = 6 6x - 5y = 14 ​

Answer 1

x = 4

y = 2

Explanation:

Rewrite x + y = 6 to make y the subject:

⇒ y = 6 - x

Substitute y = 6 - x into 6x - 5y = 14 and solve for x:

⇒ 6x - 5(6 - x) = 14

⇒ 6x - 30 + 5x = 14

⇒ 11x - 30 = 14

⇒ 11x = 44

⇒ x = 4

Substitute x = 4 into x + y = 6 and solve for y:

⇒ 4 + y = 6

⇒ y = 2

Answer 2

• (4, 2)

Explanation:

Given system:

• x + y = 6
• 6x - 5y = 14 ​

Solve by elimination, multiply the first equation by 5 and add up equations:

• 5x + 5y + 6x - 5y = 5*6 + 14
• 11x = 44
• x = 4

Find y:

• 4 + y = 6
• y = 6 - 4
• y = 2