7x + 1 = x + 7
7(1) + 1 = 8
1 + 7 = 8
If you substitute 1 for x, the statement is true. Therefore, x = 1.
Here a right angled triangle given. We know that one angle of a right angled triangle is 90°.
As the sum of three angles of a triangle is 180°, so we can say the sum of other two angles of a right angled triangle is (180-90)° = 90°.
Here in the figure the other two angles given
and
. Sum of these two angles is 90°.
So we can write the equation as,

We have to remove the parenthesis now.

Now we will add the like terms. Here x and 2x are like terms. By adding them we will get,

To solve it for x, now we have to move 15 to the other side by subtracting it from both sides.



Now to get x, we have to move 3 to the other side, by dividing it to both sides.



We have got the required value of x.
The solution is x= 25.
Answer:
(3, -6)
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- 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)
- Terms/Coefficients
- Solving systems of equations using substitution/elimination
Step-by-step explanation:
<u>Step 1: Define Systems</u>
y = 4x - 18
y = -5x + 9
<u>Step 2: Solve for </u><em><u>x</u></em>
<em>Substitution</em>
- Substitute in <em>y</em> [2nd Equation]: 4x - 18 = -5x + 9
- [Addition Property of Equality] Add 5x on both sides: 9x - 18 = 9
- [Addition Property of Equality] Add 18 on both sides: 9x = 27
- [Division Property of Equality] Divide 9 on both sides: x = 3
<u>Step 3: Solve for </u><em><u>y</u></em>
- Substitute in <em>x</em> [1st Equation]: y = 4(3) - 18
- Multiply: y = 12 - 18
- Subtract: y = -6
Its called amortization schedule