Step-by-step explanation:
Let's translate the verbal language to algebraic language.
She rides to and from school 5 days per week, 6.25 miles each route => 5*2*6.25 miles = 62.5 miles.
She rides additioanly around the park 2.5 miles for each trip t => 2.5*t = 2.5t
Total miles of her rides per week: 62.5 miles + 2.5t
She wants to ride minimum 85 miles => 62.5 + 2.5t ≥ 85
Then, the situation is represented by this inequality:
2.5t + 62.5 ≥ 85
You can develop it and get to several equivalent inequalities, for example:
2.5t ≥ 85 - 62.5
2.5t ≥ 22.5
t ≥ 9
Any of the four forms are equivalent and a valid answer.
So since you gave all of the equations of everyone's amount that they put in, it saves some work.
Let's add up everyone's contribution and then solve for x:

Then since we know the television costs $2,000, we can set this expression equal to that and simplify terms. Then we can solve for x:



So since Ronnie put in 'x', we can say that Ronnie paid $70.
Since Mark put in '2x + 500', we can plug in 70 for x to find that Mark paid $640.
And since Lisa put in '650 + 2x + 500', we can plug in 70 for x again to find that Lisa paid $1,290.
The number is x
it is negative
the square is 28 more than 3 times itself
x²=28+3x
minus (28+3x)
x²-3x-28=0
factor
(x-7)(x+4)=0
set to zero
x-7=0
x=7
this is not the answer because we were told the number was negative
x+4=0
x=-4
correct
the number is -4
test
(-4)²=28+3(-4)
16=28-12
16=16
check
the number is -4
Answer:
Height of fir tree = 9 meters
height of pine tree= 12 meters
Step-by-step explanation:
The combined height of one fir tree and one pine tree is 21 meters. The height of 4 fir trees stacked on top of each other is 24 meters taller than one pine tree.
Let x be the height of fir tree and y be the height of pine tree

Subtract x from both sides

height of 4 fir trees = pine tree +24

Substitute 21-x or y in the above equation

Add x on both sides

Divide by 5 on both sides
x=9
Now plug in 9 for x and find out y


y=12
Height of fir tree = 9 meters
height of pine tree= 12 meters
Answer:
it would be C
Step-by-step explanation:
5(10%)+25%