Answer:
? = 7.
Step-by-step explanation:
The two triangles are similar because of the AA Theorem.
The larger triangle's side that is equal to 9 + 3 corresponds to the smaller triangle's side length of 9, while the larger triangle's 21 + ? side corresponds to the smaller triangle's 21 side. Now, we can set up a proportion!




? + 21 = 7 * 4
? + 21 = 28
? = 28 - 21
? = 7
Hope this helps!
5x+6y=18
5x=18-6y
x=(18-6y)/5
Use that in the other equation
18(18-6y)/5 - 15y = 36
64.8-21.6y - 15y = 36
28.8=36.6y
.7868=y
Now put that number in for y on the first equation
5x+6(.78) = 18
5x + 4.68 = 18
5x = 13.32
x = 2.66
and y = .78
Answer:
b) 50
Step-by-step explanation:
750/15 = 50
10+14+40= 64 ounces
16 ounces = 1 pound
64/16 = 4 pounds
Substitute the x-value into the expression and solve it.
-x^{2} - 4x Substitute all the x variables for 3
-3^{2} - 4(3) Use PEMDAS and start with the exponent (-3^{2} = -3 x -3 = 9)
9 - 4(3) Multiply
9 - 12 Subtract
-3