Jennifer scored 87% on the test meaning she earned 87% of the possible points on the test. There were 180 possible points on the test so she earned 180 x 0.87 = 156 points. Each question is worth 3 points so she got \( \frac{156}{3} \) = 52 questions right.

A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.

The number of students taking German or Spanish is 10 + 9 = 19. Of that group of 19, 2 are taking both languages so they've been counted twice (once in the German group and once in the Spanish group). Subtracting them out leaves 19 - 2 = 17 who are taking at least one language. 24 - 17 = 7 students who are not taking either language.

To multiply terms with exponents, the base of both exponents must be the same. In this case they are so multiply the coefficients and add the exponents:

-8y⁷ x y⁶
(-8 x 1)y^{(7 + 6)}
-8y¹³

To multiply fractions, multiply the numerators together and then multiply the denominators together:

\( \frac{2}{8} \) x \( \frac{3}{7} \) = \( \frac{2 x 3}{8 x 7} \) = \( \frac{6}{56} \) = \(\frac{3}{28}\)