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 :)
Answer:

Step-by-step explanation:

Thr answer is the slope.
First, put the equation of the line giveninto slope-intercept form by solving fory. You get y = 2x +5, so the slope is –2.Perpendicular lines have opposite-reciprocal slopes, so the slope of theline we want to find is 1/2. answer y=-1/2
Answer:
The correct answer would be 
Step-by-step explanation:
given
we want to solve for a
How?
We can do this by using basic algebra ( isolating the variable (a ))
Step 1 subtract
from each side

now we have 
step 2 take the square root of each side

we're left with
Hence your answer is A
An ??????
Well to figure this out, we will use mathematics. You do 90% of the an and then do 39 which is close to 90 and then because it has 9 in the number that is given. So, 213 is incorrect. 90% of the things like 213, = 39. And if it equals 39, then here comes 90. 90 comes in as a number to help, but 213 does to. So we will divide the number 9. 9 = 2, and since 213 has the first digit 2 in the number, that means that the answer is An number that equals 2 is the common side of two consecutive angles in a polygon.
Just a answer!