Eight *(a number) plus 5*(another number) is -13.
translates to:
8(x) + 5(y) = -13
The sum of (the number) and (the other number) is 1.
translates to:
(x) + (y) = 1
We have a system of two equations involving two unknowns: x and y.

We can easily solve the system using Substitution or Elimination. Let's use Elimination this time.
We'll multiply the second equation by -8 so that the x's match up.

When we add the equations together, the x's will fall out of the equation, summing to zero. The 5y and -8y will sum to -3y and the right hand side will sum to -21.

Divide by -3,

Plug back into one of your original equations to find the value of x,

Subtract 7,
Answer:
∫
= 
Step-by-step explanation:
To find:
∫
Solution:
Method of substitution:
Let 
Differentiate both sides with respect to 

[use
]
So,
∫
= ∫
=
where
is a variable.
(Use ∫
)
Put 
∫
= 
Use 
So,
∫
= 
where 
Without using substitution:
∫
= ∫
= 
So, same answer is obtained in both the cases.
Answer:
90 cubes.
Step-by-step explanation:
First we find volume of the cuboid.
Volume = l x b x h = 20 x 18 x 16 = 5760 cm³
Now,
Volume of a single cube = l³ = 4³ = 64
No of cubes that can be cut out from the cuboid is
= Volume of cuboid/ volume of cube
= 5760/ 64
= 90 cubes
Answer:
64 square inches
Step-by-step explanation:
You can split this figure into a rectangle and triangle to find the area.
A= l * w
A= 5 * 12
Area of the rectangle = 60 sq in
A= 1/2 bh
b= 12-8 = 4
h= 7-5 =2
A= 1/2 (4)(2)
Area of the triangle = 4 sq in
60 + 4 = 64 sq in
Given equation is y=2x+7 and 
Let's simplify the 2nd equation
before we can start graph so that calculation will be easy

multiply both sides by 2 to cancel out fractions

y=2x+7
which is exactly same as the first equatoin so graph of both will be exactly same and solution will be infinitely many solutions.
y=2x+7 has y-intercept 7 so first point will be (0,7). Slope is 2 so rise 2 unit up then 1 right and graph the new point.