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GREYUIT [131]
3 years ago
8

I don't understand the substitution method?

Mathematics
1 answer:
liq [111]3 years ago
6 0
It depends on what variable you are tying to solve for first. Say you are trying to solve for x first and then y on the first problem you wrote.

In substitution you solve one of the equations for example with
6x+2y=-10
2x+2y=-10
you solve 2x+2y=-10 for x

2x+2y=-10
-2y = -2y (what you do to one side of the = you do to the other)
2x=-10-2y (to get the variable by its self you divide the # and the variable)
/2=/2 (-10/2=-5 and -2y/2= -y or -1y, they are the same either way)
x=-5-y

now you put that in your original equation that you didn't solve for:
6(-5-y)+2y=-10 solve for that
-30-6y+2y=-10 combine like terms
-30-4y=-10 get the y alone and to do this you first get the -30 away from it
+30=+30
-4y=20 divide the -4 from each side
/-4=/-4 (20/-4=-5)
y=-5

now the equation you previously solved for x can be solved for y.
x=-5-y
x=-5-(-5) a minus parenthesis negative -(- gives you a positive
-5+5=0
x=0

and now we have solved the problem. x=0 and y=-5

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Help please!! Quick
Finger [1]

Step-by-step explanation:

Solve for a:

Step 1: Multiply both sides by b.

b=a

Step 2: Flip the equation.

a=b

---------------------------

Solve for b:

Step 1: Multiply both sides by b.

b=a

4 0
3 years ago
On a circle of radius 10 feet, what angle would subtend an arc of length 1 feet?
Alenkasestr [34]
\bf s=\cfrac{r\theta \pi }{180}\quad 
\begin{cases}
r=radius\\
\theta=\textit{angle in degrees}\\
s=\textit{arc's length}\\
--------------\\
r=10\\
s=1
\end{cases}
\\\\\\
1=\cfrac{10\cdot \theta\cdot \pi }{180}\impliedby \textit{solve for }\theta
6 0
3 years ago
Jason decided to look at new trucks. Jason found a used truck for 34,000 dollars. A new truck is 40,000 dollars so what percent
nexus9112 [7]

Answer:

Percent of rise of a new truck on a used truck  = 15%

Step-by-step explanation:

Let x be the percentage of saved money if Jason buying a used truck.

Given:

Price of the used truck = $34,000

Price of the new truck = $40,000

We need to find the percent of rise Jason saves on a used truck rather than buying a new truck

Solution:

Using a percentage formula.

percentage\ cost = \frac{(100-x)}{100}\times Original\ cost

Substitute Percentage cost = 34,000 and Original cost = 40,000 in above formula.

34000 = \frac{(100-x)}{100}\times 40000

34000 = (100-x)\times 400                    (\frac{40000}{100}=400)

Using cross multiplication rule.

(100-x)=\frac{34000}{400}

85=100-x

x = 100-85

x = 15%

Therefore, Jason used 15% rise of a new truck for a used truck.

6 0
3 years ago
4n - 9 = -9 how do u solve?
Ede4ka [16]
Add 9 to both sides to get 4n=0 so n=0

8 0
3 years ago
Read 2 more answers
The sides of a rectangle are in the ratio 2:5. If the longer side of the rectangle is 25.5
Ksju [112]

Answer: The width of the rectangle is 10.2 inches, the perimeter is 71.4 inches,  the area is 260.1 inches.

Step-by-step explanation:

25.5/5=5.1

5.1*2=10.2

The width is 10.2 inches

25.5*2+10.2*2=71.4

The perimeter is 71.4 inches

20.5*10.2=260.1

The area is 260.1

5 0
3 years ago
Read 2 more answers
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