$\displaystyle\\
15(2a - 2) = 5(a^2 -1) \\ \\ 
30a - 30 = 5a^2-5\\\\
-5a^2 + 30a -30 + 5 =0\\\\
-5a^2 + 30a -25 =0 ~~~~~\Big| \times (-1) \\\\
5a^2 - 30a +25 = 0~~~~~\Big| : 5 \\\\
a^2 - 6a +5 = 0 \\ \\ 
a_{12}= \frac{-b\pm \sqrt{b^2-4ac}}{2a}= \frac{6\pm \sqrt{36-20}}{2}= \frac{6\pm \sqrt{16}}{2}=\frac{6\pm 4}{2}= \boxed{3\pm 2} \\ \\ 
a_1 = 3+ 2 = \boxed{5}\\\\
a_2 = 3-2 = \boxed{1}$

8 0

3 years ago

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a bus ride for a student costs $2.00 a monthly bus pass costs $44.00 which inequality represents the number c of tumed that a st

aalyn [17]

Answer: yes your right good job!

Step-by-step explanation:

5 0

3 years ago

The information for two pay as you go cell phone companies is given

Serggg [28]

One company wants $10 per 3.5 hours, so they want 10 / 3.5 ≈ 2,86 dollars per hour (after rounding to the closest hundreths).

Second company wants $1.25 per half an hour, so they want 2 * 1,25 = 2,50 dollars per hour.

The unit rate is 2,86:2,50

5 0

3 years ago

Solve: 3 x (3 + 12/3)-4=<br>

Zarrin [17]

Answer:

I get 17.

Step-by-step explanation:

Reduce the fraction:

3 ( 3 + 4 ) - 4

Add the numbers:

3 x 7 - 4

Multiply the numbers:

21 - 4

Subtract the numbers:

5 0

3 years ago

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