Real-life and equivalent expressions
Answers are for parents and teachers.
1
A shop sells pens at 7 LE each and a pen bag for 5 LE. Write the cost of n pens and a bag, then find it for n = 4.
7n + 5. For n = 4: 28 + 5 = 33 LE.
2
Test 4(x + 2) and 4x + 8 with x = 1 and x = 3. Are they equivalent?
x = 1: 12 and 12. x = 3: 20 and 20. They agree, so they are equivalent.
3
Simplify 9x + 2x + 7.
11x + 7.
4
Expand 6(m + 3).
6m + 18.
5
A friend says x + x = x². Show with a number that this is wrong.
Take x = 3: x + x = 6 but x² = 9, so they are not equal.