Answer:
-3
Step-by-step explanation:
f(x) = x2 – 4
replace x with -1
f(-1) = (-1)^2 – 4
= -3
Answer:
Step-by-step explanation:
Let the other side of the rectangle be y. The perimeter of the rectangle is expressed as P = 2(x+y)
Given P = 30ft, on substituting P = 30 into the expression;
30 = 2(x+y)
x+y = 15
y = 15-x
Also since the area of the rectangle is xy;
A = xy
Substitute y = 15-x into the area;
A = x(15-x)
A = 15x-x²
The function that models its area A in terms of the length x of one of its sides is A = 15x-x²
The side of length x yields the greatest area when dA/dx = 0
dA/dx = 15-2x
15-2x = 0
-2x = -15
x = -15/-2
x = 7.5 ft
Hence the side length, x that yields the greatest area is 7.5ft.
Since y = 15-x
y = 15-7.5
y = 7.5
Area of the rectangle = 7.5*7.5
Area of the rectangle = 56.25ft²
Since the ratio of mother to daughter is 4:1, the weight of the mother and daughter together is five times the weight of the daughter.
In fact, if the daughter weights 
pound, the mother weights 
pounds, and the total weight is 
.
We know that this total is 185 pounds, so we have
So, the daughter weights 37 pounds.
She paid $18.33 for her fabric.
3*5=15
2/3*5=3.333
15+3.333+18.333. or $18.33
Answer:
(3, - 1 )
Step-by-step explanation:
Given the 2 equations
3x + y = 8 → (1)
7x - 4y = 25 → (2)
Multiplying (1) by 4 and adding to (2) will eliminate the y- term
12x + 4y = 32 → (3)
Add (2) and (3) term by term to eliminate y
19x + 0 = 57
19x = 57 ( divide both sides by 19 )
x = 3
Substitute x = 3 into either of the 2 equations and solve for y
Substituting into (1)
3(3) + y = 8
9 + y = 8 ( subtract 9 from both sides )
y = - 1
solution is (3, - 1 )
