Coaching Centre
Substitution
Evaluating algebraic expressions and formulas by substituting numbers for pronumerals, using the order of operations.
Substituting values
Find $4a + 3b$ when $a = 5$ and $b = 2$.
Find $\dfrac{x^2 + 1}{y}$ when $x = 3$ and $y = 2$.
Formulas
A rectangle's perimeter is $P = 2l + 2w$. Find $P$ when $l = 12$ cm and $w = 7$ cm.
Find $4a + 3b$ when $a = 5$, $b = 2$.
$20 + 6$.
Find $\dfrac{x^2 + 1}{y}$ when $x = 3$, $y = 2$.
$\tfrac{10}{2}$.
Find $P = 2l + 2w$ when $l = 12$, $w = 7$.
$24 + 14$.
Find $3a$ when $a = 5$.
$3 \times 5$.
Find $abc$ when $a = 1$, $b = 3$, $c = 7$.
$1 \times 3 \times 7$.
Find $2(m + 9)$ when $m = 5$.
$2 \times 14$.
Find $2x^2$ when $x = 5$.
$2 \times 25$. Square first.
Celsius to Fahrenheit: $F = 1.8C + 32$. Find $F$ when $C = 25$.
$45 + 32$.
New numbers every time. Keep going until you get five in a row.