Answer:
B
Step-by-step explanation:
3 rectangles are 3 x 7 x 2 = 42
2 triangles are 2 x 1/2 x 2 x 
= 2
note that you have to use Pythagoras Theorem to solve for the height of the triangle
Answer:
Mary- $18
Jane- $30
Step-by-step explanation:
Add the numbers in the ratio together to get 8, and multiply 8 by the variable of x. Divide the total amount of money that both girls earned by 8. You will get x=6. Multiply 6 by 3 to get the amount of money Mary earned, which is 18, and multiply 6 by 5 to get the amount of money Jane earned, which is 30.
x(3+5) = $48
3x + 5x = $48
8x = $48
8x/8 = $48/8
x = $6
3($6):5($6) = $18:$30
Question is confusing but 12/15 divides to 4/5 or rounds to 1
The Answer is b: x = 18, y = -20
Proof:
Solve the following system:
{4 x + 3 y = 12 | (equation 1)
{7 x + 5 y = 26 | (equation 2)
Swap equation 1 with equation 2:
{7 x + 5 y = 26 | (equation 1)
{4 x + 3 y = 12 | (equation 2)
Subtract 4/7 × (equation 1) from equation 2:
{7 x + 5 y = 26 | (equation 1)
{0 x+y/7 = (-20)/7 | (equation 2)
Multiply equation 2 by 7:
{7 x + 5 y = 26 | (equation 1)
{0 x+y = -20 | (equation 2)
Subtract 5 × (equation 2) from equation 1:
{7 x+0 y = 126 | (equation 1)
{0 x+y = -20 | (equation 2)
Divide equation 1 by 7:
{x+0 y = 18 | (equation 1)
{0 x+y = -20 | (equation 2)
Collect results:
Answer: {x = 18, y = -20
