First what we gonna do is solve for y.
x+5y=28 Subtract 5y both sides.
-5y -5y
x=-5y+28 Then you have to replace x with the equation.
2(-5y+28)+3y=21 Multiply.
-10y+56+3y=21 Combine like terms and subtract 56 both sides.
-56 -56
-7y=-35 Divide -7 both sides.
y=5 Simplify.
x=-5(5)+28 Multiply and add.
x=-25+28
x=3
Heres your answer x=3 and y=5.
Answer:

General Formulas and Concepts:
<u>Calculus</u>
Differentiation
- Derivatives
- Derivative Notation
Derivative Property [Multiplied Constant]: ![\displaystyle \frac{d}{dx} [cf(x)] = c \cdot f'(x)](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7Bd%7D%7Bdx%7D%20%5Bcf%28x%29%5D%20%3D%20c%20%5Ccdot%20f%27%28x%29)
Basic Power Rule:
- f(x) = cxⁿ
- f’(x) = c·nxⁿ⁻¹
Integration
Integration Rule [Fundamental Theorem of Calculus 1]: 
Integration Property [Multiplied Constant]: 
U-Substitution
Step-by-step explanation:
<u>Step 1: Define</u>
<em>Identify</em>

<u>Step 2: Integrate Pt. 1</u>
<em>Identify variables for u-substitution.</em>
- Set <em>u</em>:

- [<em>u</em>] Differentiate [Basic Power Rule, Derivative Properties]:

- [Bounds] Switch:

<u>Step 3: Integrate Pt. 2</u>
- [Integral] Rewrite [Integration Property - Multiplied Constant]:

- [Integral] U-Substitution:

- [Integral] Exponential Integration:

- Evaluate [Integration Rule - Fundamental Theorem of Calculus 1]:

- Simplify:

Topic: AP Calculus AB/BC (Calculus I/I + II)
Unit: Integration
Answer:
2x − 3y = 9 2 x - 3 y = 9 The slope-intercept form is y = mx+ b y = m x + b, where m m is the slope and b b is the y-intercept. y = mx +b y = m x + b Rewrite in slope-intercept form.
Step-by-step explanation:
answer is y = 2/3x-3
Looks good for high school math make sure the teacher sees you're work clearly and know what the numbers are overall you should be good