10 boys equals 70 pockets
7 girls equals 77 pockets
that equals 147 pockets and 17 heads
Answer:
the first option is the right answer.
- Discriminant Formula: b² - 4ac, with a = x^2 coefficient, b = x coefficient, and c = constant
So firstly, using our equation plug in the values into the discriminant formula and solve as such:
(-7)² - 4 × 3 × 4
49 - 48
1
So our discriminant is 1. <u>Since 1 is positive and a perfect square, this means that there are 2 real, rational solutions.</u>
For this case we can make the following rule of three:
21 ------> 70%
x --------> 100%
Clearing x we have:
x = (100/70) * (21)
Rewriting we have:
x = (10/7) * (21)
x = 30
Thus,
21 is 70% of 30
Answer:
21 is 70% of 30
4 * 45 = 180
265 - 180 = 85
85/5 = 17
They sold 17 rolls of patterned wrapping paper.
