Answer: 3(2)^2 + 4(3)^2
Step-by-step explanation:
First do what is replacing the variables by changing X to 2 and Y to -3
3(2)^2 + 4(-3)^2 = 3(4) + 4(9) = 12 + 36 = 48
B) Side length of B to side length of C is 4:5.
Perimeter of C is 280, so let's put that into the side length of C's place:
4:280
But the 4 also would have to change so let's figure out how much we multiplied 5 by to get 280:
280 / 5 = 56
So let's do 4 x 56 = 224
Our new ratio is 224:280
Therefore the perimeter of mirror B is 224cm.
C) Side length of A to side length of B is 3:4.
We know the perimeter of B from the previous part (224) so let's put that in the 4s place:
3:224
But we also have to change 3, so let's figure out how much we multiplied 4 by to get 224:
224 / 4 = 56
Therefore to determine A's perimeter we do 3 x 56 = 168.
Mirror A's perimeter is 168cm.
D) The side length of mirror A is the perimeter divided by 4 (as they are squares).
168 / 4 = 42. Side length of mirror A is 42cm.
E) Area of a square is side length squared, so the area of mirror A is 42².
42² = 1,764cm².
Answer:
64v
Step-by-step explanation:
2(5v+6)-6(-9v+2)
Distribute the 2 to everything in the parentheses.
10v+12-6(-9v+2)
Distribute the -6 to everything in the parentheses.
10v+12+54v-12
Combine like terms
64v
hypotenuse (h) = 17 cm
using area of a triangle formula to solve for x
A = 
bh ( b is the base and h the height )
× 5x(3x - 1 ) =60 ( multiply through by 2 )
5x(3x - 1)=120
15x² - 5x - 120 = 0 ← in standard form ( divide all terms by 5 )
3x² - x - 24 = 0
consider the factors of the product 3 × - 24 = - 72 which sum to - 1
The factors are - 9 and + 8 ( split the middle term using these factors )
3x² - 9x + 8x - 24 = 0 ( factor by grouping )
3x(x - 3) + 8(x - 3) = 0 ( take out common factor (x - 3) )
(x - 3 )(3x + 8) = 0 ( equate each factor to zero and solve for x )
x - 3 = 0 ⇒ x = 3
3x + 8 = 0 ⇒ x = - 
x > 0 ⇒ x = 3
the sides are 5x = 15 and 3x - 1 = 8
h = √(15² + 8² ) = √(225 + 64 ) = 17 ← ( hypotenuse )
Answer:
the answer is c
Step-by-step explanation:
