Answer key · Set C
Same Number, Two Ways: More
148 6 × 5 = 30 and 6 × 3 = 18. 30 + 18 = 48, the same as 6 × 8.
263 Multiply the 9 by each part inside: 9 × x = 9x and 9 × 7 = 63.
311 4n, 6n and n (which is 1n): 4 + 6 + 1 = 11.
433n + 44 11 × 3n = 33n and 11 × 4 = 44. Multiply both parts inside the bracket.
510n − 15 5 × 2n = 10n and 5 × 3 = 15. Multiply both parts inside the bracket, and keep the minus.
63 7 × 3y = 21y, so 21y = 7 × 3y. And 7 × 2 = 14.
73 8 × 3n = 24n, so 24n = 8 × 3n. And 8 × 2 = 16.
8True 3 × 2x = 6x and 3 × 3 = 9, so 3(2x + 3) = 6x + 9. Testing numbers agrees.
9False 2(x + 5) = 2x + 10. Then 2x + 10 + 3x = 5x + 10, not 5x + 5. The table shows different numbers.
101-B, 2-C, 3-D, 4-A Break the bracket apart first, then add the a terms and the plain numbers.
1148 6 + 3 = 9 and 4 × 9 = 36. Then 2 × 6 = 12. 36 + 12 = 48.
124(x + 5) Area is width times length: 4 × (x + 5), written 4(x + 5). The 4 multiplies both parts.
136(3x + 12) 6(3x + 12) = 18x + 72. The other three all give 18x + 12.
14Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.