Lets use x as the number of CD's that she will buy in a month. So knowing that, our inequality can look like this. 7 + 10x < or = 100. Why? because we will have to multiply 10 with the number of CDs she will purchase in a month to get the total she spends. Hence 10 times x. She also has to add a 7 membership fee per month to this. Also, she has to remember that what she paid has to be less or equal to 100 because the problem states that she spends no more than 100 a month.
So there are x girls and x-4 boys and together they make 28:
x+x-4=28
2x-4=28
2x=32
x=16
so there are 16 girls and 12 boys.
the ratio is then 16:12, or we can simplify (by dividing both sides by 4): 4:3
so the best answer is 4:3.
Answer:
2$+(1.29$ x 30)=40.70$
Step-by-step explanation:
Answer:
5.5 days (nearest tenth)
Step-by-step explanation:
<u>Given formula:</u>

= initial mass (at time t=0)- N = mass (at time t)
- k = a positive constant
- t = time (in days)
Given values:
= 11 g- k = 0.125
Half-life: The <u>time</u> required for a quantity to reduce to <u>half of its initial value</u>.
To find the time it takes (in days) for the substance to reduce to half of its initial value, substitute the given values into the formula and set N to half of the initial mass, then solve for t:

Therefore, the substance's half-life is 5.5 days (nearest tenth).
Learn more about solving exponential equations here:
brainly.com/question/28016999
Answer:
13) 90-18 = 72
14) 108/9 = 12
15) 66+34 = 100
16) 7*8 = 56
Step-by-step explanation:
All you need to do is take the second term of each equation and move it to the other side. So for number 16 we just need to move the 8 from the left to the right. This is as simple as multiplying both sides by 8 to get:
8*(56/8) = 8(7)
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56 = 8*7
And that would be the answer to number 16!