Question

Y=3x-5 and y=1/2x+5 Write your answer as an ordered pair, (x,y).

Answer 1

use the substitution method

y=3x-5

y= 1/2x+5

3x-5= 1/2x+5

move -5 to the other side

sign changes from -5 to +5

3x-5+5= 1/2x+5+5

3x= 1/2x+10

move 1/2x to the other

3x-1/2x= 1/2x-1/12x+10

3x-1/2x= 10

find the common denominator for 3x

pretend that there is a 1 for 3x. 3x/1. The common denominator is 2. Mutiply the fraction by 2

3x(2)/1(2)

= 6x/2

6x/2-1/2x= 10

5/2x= 10

mutiply both sides by 2/5

5/2x(2/5)= 10(2/5)

Cross out 5 and 10, divide by 5 . Then becomes 2*2= 4

x= 4

find y by using the substitution method

y=3x-5

y= 3(4)-5

y= 12-5

y= 7

Answer: (4,7)