Answer:

Step-by-step explanation:
-2x + 2y = -4 (times 3) -6x + 6y = -12
3x + 3y = -18 (times 2) 6x + 6y = -36
.
-6x + 6y = -12
<u>6x + 6y = -36 </u>+
12y = -48

y = -4
.
Substitute the value of y to the one of equations
-2x + 2(-4) = -4
-2x - 8 = -4
-2x = -4 + 8
-2x = 4

x = -2
Hope this picture helps! ;) Ignore the stuff around it ($12 or the triangle)
Answer:
No. Remember, a right angle must have a 90 degree angle. We can find the lengths with the Pythagorean Theorem.
Step-by-step explanation:
Given the length 7, 10, and 12, we can assume that 12 is the hypotenuse (it is the longest length).
- we can use 7 and 10 interchangeably.
Fill in the equation, 
where c = 12, and a or b = 7 or 10.
To indicate if the given lengths would form a right angle, we can only input 7 or 10, not both.
Therefore,
or 
==> 49 + b^2 = 144 ==> <u>b= </u>
<u> ==> </u><u>9.746</u>
b= 9.7, not 10.
==> 100 + b^2 = 144 ==> <u>b = </u>
<u> ==> </u><u>6.633 </u>
b= 6.6, not 7.
Therefore, the lengths 7, 10, and 12, does NOT make a right triangle.
Hope this helps!
Answer:
7.35
Step-by-step explanation:
4.25+2.75=7.00 before tax
7.00 x .05=.35 sales tax
7.00+ .35=7.35 total bill