Algebra One: factoring, etc. 10 points.?

Question

Hi,

I am unsure on some of my algebra problems so please give all the help you can.

Solve by factoring.

2y^2 + 4 = 9y

Don't you convert this to = 0? I did that but cannot figure out what multiplies to four but adds to nine. Please help.

Factor Completely.

ax^2 - 18ax + 77a

Systems of Equations

The Rooney family drives to Pittsburgh at 60 mph and returns by a road 10 miles shorter at 65 mph. The return trip takes 30 minutes less. How long is each road?

Last one-

Solve algebraically for the indicated variable. Put all answers in exact value form.

2/7(x - 3) = 1/4 [ x - 2/3 + 4 ]

Any help will be greatly appreciated. I will give 10 points to the person with the most accurate info. Thank you so much in advance!

Answer 1

the first one should be:

(2y-1)(y-4)=0

2y-1=0                    y-4=0

2y=1                       y=4

y=1/2

you werent finding any multiples that added to 9 because you were forgetting that you have to have a 2y in there so when you FOIL it becomes

2y^2-8y-y+4=0 which simplifies into

2y^2-9y+4

hope this helps and hope you know what FOIL means otherwise i probably just confused you. if not, FOIL stands for

First

Outside

Inside

Last

its the order that you multiply the two sets of numbers

(2y-1) (y-4)

you would multiply:

2y by y = 2y^2 (first numbers in each set)

2y by -4 = -8y (outside numbers in each set)

-1 by y = -y (inside numbers in each set)

-1 by -4 = 4 (last numbers in each set)

if you add up all the final answers you end up with your original equation so you know you did it right. hope this helped and didnt confuse you even more. its kind of hard to explain on a computer

Answer 2

Hi,

Solve by factoring.

2y^2 + 4 = 9y

2y² + 4 = 9y

2y² - 9y + 4 = 0

(y - 4)(2y - 1) = 0

y - 4 = 0

y = 4

2y - 1 = 0

2y = 1

y = 1/2

Factor Completely.

ax^2 - 18ax + 77a

ax² - 18ax + 77a =



a(x² - 18x + 77) =

a(x - 11)(x - 7) <==ANSWER

Systems of Equations

The Rooney family drives to Pittsburgh at 60 mph and returns by a road 10 miles shorter at 65 mph. The return trip takes 30 minutes less. How long is each road?

x/60 - (x - 10)/65 = 1/2

Multiply by 156 to eliminate fractions.

13x - 12(x - 10)/5 = 78

Multiply by 5 for the fraction I forgot.

65x - 12x + 120 = 390

53x = 270

not right but I'll fix it at home

Last one-

Solve algebraically for the indicated variable. Put all answers in exact value form.

2/7(x - 3) = 1/4 [ x - 2/3 + 4 ]

coming

Answer 3

2y^2+2^2=3^2