Which of the following statements are true? select all that apply.
1. for all real numbers a and b, a+b=b+a
2. for all real numbers a and b, ab=ba
3. for all real numbers a and b, a-b=b-a
4. for all real numbers a, b and c, (a+b) + c = a + (b+c)
5. for all real numbers a, b and c, (a-b) - c = a - (b-c)
6. for all real numbers a, b and c, a(b+c)= ab+ac

d) 48

step-by-step explanation:

16,32,48,64,80,96,112,128,144,160,176,192,208,224,240,256,272,288,304,320,336

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w