Alright, lets get started.
Justin is asked to solve the linear equations using elimination method.
By using elimination method means we have to multiply some numbers in our given equations in such a way that the co-efficient of x or y become same in both equations so that we could add or subtract them to cancel one of the term either x or y.
So, given equations are :


See we have 5x in first equation and -20x in second equation.
So, we try to change 5x into 20 x by multiplying it with 4, both of the equations will have 20 x in common
Lets multiply 4 in first equation


Now both equations could be added and 20 x will be cancelled out and we could easily find the value of y then solve for x.
So, Justin should try to change 5 so that it will be cancels, so option B : Answer
Hope it will help :)
<h3>
Answer: 112</h3>
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Explanation:
The angle adjacent to the 146 degree angle is 180-146 = 34 degrees.
In other words, the angles 34 and 146 combine to 180. These angles are supplementary.
The tickmarks on this triangle tell us it is isosceles. The angles opposite the congruent sides are congruent angles. So the unmarked interior angles (not marked x) are 34 degrees each.
Now use the fact that any triangle has its interior angles always add to 180
x+34+34 = 180
x+68 = 180
x = 180-68
x = 112