For #7 - part a: greatest common factor (GCF) is 5.
Part b: cross out everything BUT 10 & 20.
The identity property is shown
Solve <span>4x − 3y = 3 and 5x − 4y = 3
Step 1: Solve for x in 4x-3y=3:
4x-3y=3
4x-3y+3y=3+3y [Add 3y to both sides]
4x=3y+3
</span>

[Divide both sides by 4]
x=

Step 2: Substitute

<span> for x in 5x-4y=3
5x-4y=3
5(</span>

<span>)-4y=3
</span>


[Subtract

to both sides]


[Divide both sides by

]
<span>y = 3
Step 3: Substitute 3 for y in x = </span>


x = 3