Answer:
Multiply x + y = 3 by 3 and add it to -3x - 2y = -7
Step-by-step explanation:
When using elimination to solve a system of equations, you multiply one equation by some number. The reason for doing this is that when you add it to the second equation, you want one variable to cancel out. When one variable cancels out (in this case x), you can solve for the other variable (in this case y). I will show this:
3(x + y = 3) = 3x + 3y = 9
3x + 3y = 9
+ -3x + -2y = -7
---------------------------
y = 2
Now, knowing that y = 2, you can substitute y=2 into either equation to solve for x.
-3x - 2(2) = -7
-3x -4 = -7
-3x = -3
x = 1 | to double check (1, 2) as your answer plug these values into both equations
Finding this solution would not have been possible if not for cancelling out the x's above. The other three are wrong because none of the other options cancels out one of the variables.
Answer:
B. 40 cibic inches
Step-by-step explanation:
Hope it Help
Answer:
114 units²
Step-by-step explanation:
The opposite sides of a parallelogram are congruent, so
AB = CD , that is
13x - 7 = 5x + 9 ( subtract 5x from both sides )
8x - 7 = 9 ( add 7 to both sides )
8x = 16 ( divide both sides by 8 )
x = 2
Then
5x + 9 = 5(2) + 9 = 10 + 9 = 19
3x = 3(2) = 6
The area (A) of a parallelogram is calculated as
A = bh ( b is the base and h the perpendicular height ), thus
A = 19 × 6 = 114 units²
