Answer:
(4, 10)
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties<u>
</u>
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality<u>
</u>
<u>Algebra I</u>
- Coordinates (x, y)
- Coefficients
- Solving systems of equations using substitution/elimination
Step-by-step explanation:
<u>Step 1: Define Systems</u>
-5y + 8x = -18
5y + 2x = 58
<u>Step 2: Solve for </u><em><u>x</u></em>
<em>Elimination</em>
- Combine 2 equations: 10x = 40
- [Division Property of Equality] Divide 10 on both sides: x = 4
<u>Step 3: Solve for </u><em><u>y</u></em>
- Substitute in <em>x</em> [Original equation]: -5y + 8(4) = -18
- Multiply: -5y + 32 = -18
- [Subtraction Property of Equality] Subtract 32 on both sides: -5y = -50
- [Division Property of Equality] Divide -5 on both sides: y = 10
Hello!
There's more than one way in which to check this answer thru estimation. I'd find 6*60 and 6*70 separately, obtaining 360 and 420. It's obvious that Kendra's "390" is between 360 and 420, so it's likely that she's right.
6*65 does indeed equal 390.
Using a graph tool
case 1)
2x-y=-13
y=x+9
the solution is the point (-4,5)
see the attached figure N 1
case 2)
y=3x-7
y=2x-5
the solution is the point (2,-1)
see the attached figure N 2
case 3)
3x+2y=10
6x-y=10
the solution is the point (2,2)
see the attached figure N 3
case 4)
y=6
x=-5
the solution is the point (-5,6)
see the attached figure N 4
case 5)
4x-3y=5
3x+2y=-9
the solution is the point (-1,-3)
case 6)
x+y=7
x-y=-1
the solution is the point (3,4)
the answer in the attached figure