Year 8 CH 5G & 5H T2 Week 3

Answer explanation

To expand the expression 3(x + 4), distribute 3 to both terms inside the parentheses: 3 * x + 3 * 4 = 3x + 12. Thus, the correct answer is 3x + 12.

Answer explanation

To expand the expression 5(y - 2), distribute 5 to both terms inside the parentheses: 5 * y = 5y and 5 * -2 = -10. Thus, the expanded expression is 5y - 10, which matches the correct answer.

Answer explanation

To expand, distribute 2 into (a + 3): 2a + 6. Then add 4a: 2a + 6 + 4a = 6a + 6. Thus, the correct answer is 6a + 6.

Answer explanation

To expand, distribute 7 to (m - 1): 7m - 7. Then, add 2m: 7m - 7 + 2m = 9m - 7. Thus, the correct answer is 9m - 7.

Answer explanation

To expand -4(x - 5), distribute -4: -4 * x + (-4) * (-5) = -4x + 20. Thus, the correct expansion is -4x + 20.

Answer explanation

First, distribute 6: 6(2y) + 6(3) = 12y + 18. Then, subtract 4y: 12y + 18 - 4y = 8y + 18. Thus, the correct answer is 8y + 18.

Answer explanation

To factorise 8x + 12, find the greatest common factor, which is 4. Dividing each term by 4 gives 4(x + 3). Thus, the correct choice is 4(x + 3).

Answer explanation

To factorise 15y - 10, we can take out the common factor of 5. This gives us 5(3y - 2). However, we can also express it as 5(y - 2) by factoring out 5 from the entire expression, which matches the correct choice.

Answer explanation

To find the HCF of 18a and 24, we consider the numerical part. The factors of 18 are 1, 2, 3, 6, 9, 18, and the factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24. The highest common factor is 6, but since 'a' is not a factor, we take 12 as the highest common factor.

Answer explanation

To factorise 9m - 27, we can factor out the greatest common factor, which is 9. This gives us 9(m - 3). Thus, the correct answer is 9(m - 3).