Answer:
12 years old.
Step-by-step explanation:
1) 2x+x=18
2) Now solve 2x+x=18
Add alike terms
3x=18
Now divide both sides by 3 (3x/3 and 18/3)
x=6
So Hannah is 6 years old. Her sister must be 12.
Hey there!
<u>Use the quadratic formula to find the solution(s). x² + 2x - 8 = 0</u>
x = -4 or x = 2 ✅
<em><u>Quadratic</u></em><em><u> </u></em><em><u>formula </u></em><em><u>:</u></em><em><u> </u></em>ax² + bx + c = 0 where a ≠ 0
The number of real-number solutions <em>(roots)</em> is determined by the discriminant (b² - 4ac) :
- If b² - 4ac > 0 , There are 2 real-number solutions
- If b² - 4ac = 0 , There is 1 real-number solution.
- If b² - 4ac < 0 , There is no real-number solution.
The <em><u>roots</u></em> of the equation are determined by the following calculation:

Here, we have :
1) <u>Calculate </u><u>the </u><u>discrim</u><u>i</u><u>n</u><u>ant</u><u> </u><u>:</u>
b² - 4ac ⇔ 2² - 4(1)(-8) ⇔ 4 - (-32) ⇔ 36
b² - 4ac = 36 > 0 ; The equation admits two real-number solutions
2) <u>Calculate </u><u>the </u><u>roots </u><u>of </u><u>the </u><u>equation</u><u>:</u>
▪️ (1)

▪️ (2)

>> Therefore, your answers are x = -4 or x = 2.
Learn more about <u>quadratic equations</u>:
brainly.com/question/27638369
Answer:
40 bats sold for $42
26 bats sold for $30
Step-by-step explanation:
x + y = 66
42x + 30y = 2460
solve first equation for y and plug in for y in second equation
42x + 30 (66 - x) = 2460
x = 40
y = 66- 40 = 26
Answer:

Step-by-step explanation:
To solve this operation we need to find the common multiple of both denominators and solve for a.

Thus, the solution is 7(a -1) / (a+2)(a-5)