Answer key · Set A
Two Ways to Write the Same Thing
132 4 × 3 = 12 and 4 × 5 = 20. 12 + 20 = 32, the same as 4 × 8.
240 Multiply the 5 by each part inside: 5 × x = 5x and 5 × 8 = 40.
37 3x, x (which is 1x) and 3x: 3 + 1 + 3 = 7.
414x + 63 7 × 2x = 14x and 7 × 9 = 63. Multiply both parts inside the bracket.
5True 7 × 5 = 35 and 7 × x = 7x, so 7(5 + x) = 35 + 7x. Testing numbers agrees.
6False The 4 multiplies both parts: 4(x + 3) = 4x + 12. The table shows the two writings give different numbers.
73 6 × 3y = 18y, so 18y = 6 × 3y.
81-D, 2-A, 3-B, 4-C Break the bracket apart, add the n terms, and add the plain numbers.
92(5 + 3) There are 2 rows, and each row has 5 + 3 dots: 2(5 + 3) = 16.
1020 4 + 6 = 10, and 2 × 10 = 20.
117 Add the plain numbers: 3 + 4 = 7. Add the x terms: x + 3x = 4x.
1212(x + 18) 12(x + 18) = 12x + 216. The other three all give 12x + 18.
13Your own words: a grown-up reads it.
Mark each answer, count the right ones and write the score on the sheet.