Question

A first number plus twice a second number is 4 twice the first number plus the second totals 11 find the number

Answer 1

6

Explanation:

Let the first number be x

Let the second number be y

x + 2y= 4............equation 1

2x +y= 11............equation 2

From equation 1

x + 2y= 4

x = 4-2y

Substitute 4-2y for x in equation 2

2x + y= 11

2(4-2y) + y= 11

8-4y+y= 11

8-3y= 11

-3y= 11-8

-3y= 3

y= -1

Substitute -1 for y in equation 1

x + 2y= 4

x + 2(-1) = 4

x-2= 4

x = 4+2

x = 6

Hence the first number is 6