Solve by substitution

2x -9y = 14

x = -6y + 7

first replace the x of the first equation with the -6y + 7

which turns out

2 ( -6y + 7 ) -9y = 14

by following brackets first rule we can do

- 12y + 14 -9y = 14

we can arrange the following to

- 12y - 9y + 14 = 14

so like terms are together

we shifting 14 over

- 12y - 9y = 14 - 14

- 21y = 0

meaning y = 0

then we can replace x = -6y + 7 with

x = -6 (0) + 7

by multiplying with brackets first rule we come to

x = 0 + 7

x = 7

do you have the measurements?