Answer:
33/4
Step-by-step explanation:
Let the first number be x, and the second number be y.
x - y = 4
x + y = -7
Solve for x in the first equation.
x - y = 4
x = 4 + y
Put x as (4 + y) in the second equation and solve for y.
4 + y + y = -7
4 + 2y = -7
2y = -7 - 4
2y = -11
y = -11/2
Put y as -11/2 in the first equation and solve for x.
x - y = 4
x - (-11/2) = 4
x + 11/2 = 4
x = 4 - 11/2
x = -3/2
Their product is:
-11/2 × -3/2
33/4
I'm not sure if it only wants you to find Equation 1 or go further and solve:
x = the number of 5c coins
y = the number of 10c coins
Equation 1: the total number of coins is 65
x + y = 65
total value of $3.80
0.05x + 0.1y = 3.8
<u>Simultaneous Equations</u>
Make one coefficient the same
10 * (0.05x + 0.1y = 3.80 = 0.5x + y = 38
x + y = 65
0.5x + y = 38
Subtract the equations
(x + y) - (0.5x + y)= 65 - 38
(x - 0.5x) + (y - y) = 65 - 38
0.5x = 27
x = 54
Substitute it into the original equation to find y.
x + y = 65
54 + y = 56
y = 65 - 54 = 11
Substitute it into the other equation to check it's right.
0.05x + 0.1y = 3.8
0.05(54) + 0.1(65) = 3.8
x = 54 5c coins
y = 11 10c coins
Answer:
Step-by-step explanation:
y = -2x+5
slope of line is -2.
slope of parallel to line is also -2
point-slope equation for line of slope -2 that passes through (-5,3):
y-3 = -2(x+5)
Area of a rectangular yard:
A 1 = L x W = 7 x * 6 x = 42 x²
Area of a pool :
A 2 = r² π = ( 2 x )² π = 4 x² π
A = A 1 - A 2 = 42 x² - 4 x² π
The answer must be in terms of π:
B ) 42 x² - 4 x² π