Question

Year 9 Maths - linear equations please help

Solve the pair of simultaneous equations:
3x-y=7
y=x+5
using the substitution method to find the values of x and y.

Answer 1

X=3, Y=9
X+Y=12
Y=X+6

X+X+6=12
2X=6
X=3

Y=3+6=9

Answer 2

x=1 & y=6 or (1,6)

Explanation:

3x-x+5=7 Substitute the 2nd equation in for y

2x+5=7 Do 3x-x to get 2x

2x=2 Subtract 5 from both sides

x=1 Divide 2 from both sides

y=1+5 Insert 1 as x

y=6 Add 1+5 to solve for y

Hope this helped!