Number & Quantity - ACT Math

Factors divide evenly into a number; Multiples are what you get when you multiply a number by integers

$\dfrac{3}{5}$

$5\sqrt{2}$ ($\sqrt{50} = \sqrt{25 \times 2} = \sqrt{25} \times \sqrt{2} = 5\sqrt{2}$)

A whole number greater than 1 that has exactly two factors: 1 and itself

$0$

$64$ ($8^2 = 64$)

$6, 12, 18, 24, 30$

$2$ (all other even numbers are divisible by 2, so they're not prime)

$x^8$

$8$

$2^2 = 4$ (Add exponents in numerator: $2^7$, then subtract denominator: $2^{7-5} = 2^2$)

Parentheses $\rightarrow$ Exponents $\rightarrow$ Multiplication and Division (left to right) $\rightarrow$ Addition and Subtraction (left to right)

Order doesn't matter in addition or multiplication: $a + b = b + a$; $ab = ba$

Whole numbers and their opposites: $\ldots, -3, -2, -1, 0, 1, 2, 3, \ldots$

$3$. (Note: Cube roots preserve sign: $\sqrt[3]{-27} = -3$)

Odd (even $\times$ even $=$ even, even $+$ odd $=$ odd)

$-5, 0,$ and $7$ (integers cannot have fractional or decimal parts)

$a(b + c) = ab + ac$

$2{,}500$

$40%$