En anglais

Substituting into Formulae

Mathematics · Algebra · ages 11-12

Name ______________________ Date ____________

Evaluate x + x + 2 when x = -3.
Answer: ______________
A rectangle's area is A = l × w. Its length l is 6 cm and its width w is 9 cm. Find A in cm².
Answer: ______________
If a = 5, what is a + 3?
- 7
- 8
- 15
When you substitute into 2 + 3 × n, you should multiply before you add.
Circle one: True False
If a = 7 and b = 2, find the value of a - (-b)^3.
Answer: ______________
If a = 7 and b = 2, find the value of a - (-b)^2.
Answer: ______________
If x = -2, find the value of x cubed, written x^3.
Answer: ______________
A triangle's area is A = b × h ÷ 2. Its base b is 12 cm and its perpendicular height h is 5 cm. What is A in cm²?
- 30
- 60
- 17
The formula is A = s², where s = -4. What is A?
- -16
- 8
- 16
If a = 2, b = 3, c = 8, d = 2, e = 3, and f = 1, find the value of a × b^2 - c ÷ d^2 × e + f.
Answer: ______________

Answer key

For grown-ups. Fold this page away before handing over the rest.

-4 · Replace both occurrences: (-3) + (-3) + 2 = -6 + 2 = -4.
54 · Replace l with 6 and w with 9: A = 6 × 9 = 54 cm².
8 · Substitute a = 5: 5 + 3 = 8.
True · Multiplication has priority over addition. Calculate 3 × n before adding 2.
15 · Cubing a negative number gives a negative answer, and subtracting a negative adds instead.
3 · Work out the power first, and remember that squaring a negative number gives a positive answer.
-8 · A cube uses three copies of its base. (-2) × (-2) = 4, then 4 × (-2) = -8.
30 · Substitute both measurements: A = 12 × 5 ÷ 2 = 60 ÷ 2 = 30 cm².
16 · A negative number squared becomes positive: (-4) x (-4) = 16.
13 · Calculate powers first, then multiply and divide from left to right before adding and subtracting.