Question

Five times a number plus four times a second number is 20. Four times

the first number added by two times the second number is 16. Write the
system of equations for this situation. *

Answer 1

first number is 4

second number is 0

Explanation:

y = 1st number

x = 2nd number

system of equations:

5y + 4x = 20

4y + 2x = 16

I multiplied the second equation by -2 to eliminate the 'x-values'

-2(4y + 2x = 16) = -8y - 4x = -32

now add to 1st equation: 5y + 4x = 20

-3y = -12

y = 4

solve for 'x':

5(4) + 4x = 20

20 + 4x = 20

4x = 0

x = 0