Answer:
or 
Step-by-step explanation:
Substitution means plugging in one variable's value that consists of the opposite variable. Because 
is already specified, you can plug it into the second equation's 
value. After doing that, it looks like this:
Then you would distribute the 
across the parentheses next to it, like this:
Then, add like terms, like this:
Then divide both side by 
to isolate 
.
Now, you can plug 
() into either equation, but the first one seems simpler so you would pick that. It would look like this:
Solving would look like this:
So the answer is or .
1. 8.96 x 105 I think
2. <span>4.25 x 10-4
</span>
4x-3y=17......(1)
5x+4y=60......(2)
Multiply equation (1) by 4 and equation (2) by 3:-
16x - 12y = 68
15x + 12y = 180
Adding these 2 equations:_
31x = 248
x = 248/31 = 8
Now substitute x = 8 in equation (1):-
4(8) - 3y = 17
32-3y = 17
-3y = -15
y = -15/-3 = 5
So solution is x=8,y=5
Well if the student already finished 6 problems out of 15, there are 15-6 = 9 homework questions she still has to finish.
Still needs to complete: 9.
Already finished: 6
9 : 6.
Simplified: 3 : 2
