Answer: 3× (w +5)
Step-by-step explanation:
1. The two equations follow the slope-intercept form which y=mx + b. They have the same y-intercept which is equal to 900.
2. Suppose x= 10
Plan Alpha: y=-7x+900=-7(10)+900=830
Plan Foxtrot: y = -17x+900 = -17(10)+900=730
Between the 2 plans, the lower value is 730. Plan Foxtrot is better for reduction of pollution.
3. The city council should choose Plan Foxtrot because the reduction of pollution is much greater. Their goal would be reached faster if they go with faster reduction of pollution.
<span>The simple interest formula is:
A = P · (1 + r · t)
where:
A = total amount
P = principal
r = rate
t = time
Let's solve for r:
A = P + P · r · t
P · r · t = A - P
r = (A - P) / (P · t)
The quantity A - P is defined as the Interest, therefore:
r = I / (P <span>· t)
= 1020 / (8500 </span>· 4)
= 0.03
Therefore the rate was 3%.
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To solve this system by substitution, we must substitute in the value we are given for x in terms of y (the first equation) into the second equation. This is modeled below:
x = -8y - 15
2x + 5y = -8
2 (-8y - 15) + 5y = -8
Now, we should solve this new equation for y. To begin, we should use the distributive property to get rid of the parentheses on the left side of the equation and begin the simplification process.
-16y - 30 + 5y = -8
Next, we can combine like terms on the left side of the equation by adding together the two terms that both contain the variable y.
-11y - 30 = -8
Next, we should add 30 to both sides in order to move all of the constant (number) terms to the left side of the equation.
-11y = 22
After that, we should divide both sides of the equation by -11 in order to get the variable y alone.
y = -2
Now, we can substitute our value for y back into one of our original equations (it doesn't matter which one you choose; they will yield the same answer).
x = -8y - 15
x = -8(-2) - 15
To simplify, we should following the order of operations outlined by PEMDAS and compute the multiplication and then the subtraction.
x = 16 - 15
x = 1
Therefore, the answer to the system is x = 1 and y = -2, or (1,-2) when written as an ordered pair.
Hope this helps!
