Use the substitution method to solve:
a + s = 304
7a + 2s = 1118
Check Format
Equation 1 is in the correct format.
Check Format
Equation 2 is in the correct format.
Rearrange Equation 2 to solve for a:
7a + 2s = 1118
Subtract 2s from both sides to isolate a:
7a + 2s - 2s = 1118 - 2s
7a = 1118 - 2s
Now divide by 7:
| 7a | |
| 7 |
| = |
| 1118 - 2s |
| 7 |
Revised Equation 2:
| a = | 1118 - 2s |
| 7 |
Plug Revised Equation 2 value into a:
1(a) + s = 304
1 * ((1118 - 2s)/7) + s = 304
((1118 - 2s)/7) + s = 304
Multiply equation 1 through by 7
7 * (((1118 - 2s)/7) + s = 304)
7 * (((1118 - 2s)/7) + s = 304)
1118 - 2s + 7s = 2128
Group like terms:
-2s + 7s = 2128 - 1118
5s = 1010
Divide each side by 5
| 5s | |
| 5 |
| = |
| 1010 |
| 5 |
| s = | 1010 |
| 5 |
s = 202
Plug this answer into Equation 1
1a + 1(202) = 304
1a + 202 = 304
1a = 304 - 202
1a = 102
Divide each side by 1
| 1a | |
| 1 |
| = |
| 102 |
| 1 |
| a = | 102 |
| 1 |
a = 102
Test Your Knowledge?
- What are the 3 methods to solve a system of 2 equations?
- With the elimination method, what are you trying to eliminate?
Common Core State Standards In This Lesson
CCSS.MATH.CONTENT.8.EE.C.8,CCSS.MATH.CONTENT.8.EE.C.8.B
What is the Answer?
a = 102 and s = 202
How does the Simultaneous Equations Calculator work?
Free Simultaneous Equations Calculator - Solves a system of simultaneous equations with 2 unknowns using the following 3 methods:
1) Substitution Method (Direct Substitution)
2) Elimination Method
3) Cramers Method or Cramers Rule Pick any 3 of the methods to solve the systems of equations 2 equations 2 unknowns
This calculator has 2 inputs.
1) Substitution Method (Direct Substitution)
2) Elimination Method
3) Cramers Method or Cramers Rule Pick any 3 of the methods to solve the systems of equations 2 equations 2 unknowns
This calculator has 2 inputs.
What 1 formula is used for the Simultaneous Equations Calculator?
Δ = a * e - b * d
What 7 concepts are covered in the Simultaneous Equations Calculator?
- cramers rule
- an explicit formula for the solution of a system of linear equations with as many equations as unknowns
- eliminate
- to remove, to get rid of or put an end to
- equation
- a statement declaring two mathematical expressions are equal
- simultaneous equations
- two or more algebraic equations that share variables
- substitute
- to put in the place of another. To replace one value with another
- unknown
- a number or value we do not know
- variable
- Alphabetic character representing a number
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