volume_mute
Expand (x - 7) (6-x)
publish date: 2020/11/21 19:02:00 GMT+11
volume_mutea. x2 + 13x - 42
b. −x2 + 7x − 42
c. −x2 + 13x − 42
d. −x2 + 13x − 13
Correct Answer
c
Explanation
- Write the expression.
- (x − 7)(6 − x)
- Multiply the first terms in each bracket, then the outer terms, the inner terms and finally the last terms.
- = x × 6, x × −x, −7 × 6, −7 × −x
- Remove the brackets by multiplying each term in the brackets by the term outside the bracket. Remember to change the sign when the term outside the bracket is negative.
- = 6x − x2 − 42 + 7x
- Collect like terms.
- = −x2 + 13x − 42
Reference
Maths_Quest_10+10A_VC_Revised_Edition_Book