Hope this helps you out :D
It’s 2 equations so in order to solve the previous system, you can use different methods, as for example substitution or addition of equations. In this case, you use the second one, due to the fact you have 7x in one equation and -7x in the other equation. In this way you can easily eliminate variable x and then solve for y. With the value of y you can replace in any of the two equations and solve for x.
7x-y=-1
-7x+3y=-25
Summarizing, you proceed as follow:
- add up the given equations
7x - y = -1
-7x+3y=-25
——————
0 +2y=-26
- solve for y in the previous equation
2y=-26
y=-26/2
y=-13
- replace the obtained value of y in one of the given equations, and solve for x
7x-(-13)=-1
7x+13=-1
7x=-1-13
7x=-14
x=-14
x=-14/7
x=-2
Hence, the solution of the given systems of equation is:
X=-2
Y=-13
Answer:
a) $109
b) 
c) 
Step-by-step explanation:
a) The marginal cost, or the cost per additional unit, is given by the derivate of the cost function:
b) Profit is given by Revenue minus Cost:
c) The marginal profit for 8 units, is given by the difference in profit for 9 units and 8 units:
Answer:
1 to the left and 7 up
Step-by-step explanation:
The x coordinate goes from 3 to 2, so that is your 1 to the left.
The y coordinate goes from -4 to 3, so that is your 7 up.
Answer:
see explanation
Step-by-step explanation:
(5)
Since ∠EBA = 90° then ∠ABD = 90° ( straight angle ) and
∠ABC + ∠CBD = ∠ABD, that is
2x + 3x - 10 = 90, simplifying
5x - 10 = 90 ( add 10 to both sides )
5x = 100 ( divide both sides by 5 )
x = 20, thus
∠ABC = 2x = 2 × 20 = 40°
∠CBD = 3x - 10 = (3 × 20) - 10 = 60 - 10 = 50°
(6)
4x - 18 = 3x + 7 ( vertical angles are congruent )
Subtract 3x from both sides
x - 18 = 7 ( add 18 to both sides )
x = 25
7y = 5y + 28 ( vertical angles are congruent )
Subtract 5y from both sides
2y = 28 ( divide both sides by 2 )
y = 14
Answer: Travis paid $8.05 per light and grace paid $6.8 per light so its grace
Step-by-step explanation:
