The answer to this question is C.
Answer:
<h3>
A = 0.5(2x+6)(6x+13) = 6x² + 49x + 78</h3>
Step-by-step explanation:
H = 2x+6 - the hight
3H = 3(2x+6) - triple the hight
3H-5 = 3(2x+6) - 5 - five less than triple the height
Area of triangle: A = 0.5BH
B = 3(2x+6)-5 = 6x + 18 - 5 = 6x + 13
H = 2x+6
So:
A = 0.5(2x+6)(6x+13) = (x+6)(6x+13) = 6x² + 13x + 36x + 78
A = 6x² + 49x + 78
Answer: You can multiply the top equation by -1 to eliminate the x variable.
And the solution is (2,4/3) in case you need it.
Step-by-step explanation:
2x + 3y = 8
2x + 6y = 12
If you multiply the upper equation or down equation by one, you will be able to eliminate the x variable.
-1( 2x + 3y) = -1(8) New equation: -2x -3y = -8.
Add the new equation you got by multiplying the top equation by -1 to the bottom equation.
Add them: -2x -3y = -8
2x + 6y = 12
3y = 4
y = 4/3
You can now input the value for y into the one of the equations and solve for x.
-2x - 3(4/3) = -8
-2x -4 = -8
+4 +4
-2x = -4
x = 2