GoldenLeaf

FOIL method

FIRST

OUTER

INNER

LAST

(x + 5)(x - 5)

FIRST: (x * x) = x^2

OUTER: (x * -5) = -5x

INNER: (x * 5) = 5x

LAST: (5 * -5) = -25

x^2 - 5x + 5x - 25

The 'x's cancel each other out.

x^2 - 25 is your final answer.

For these, just use the on-site calculator

$${\mathtt{3.453\: \!125}}{\mathtt{\,\times\,}}{\mathtt{703}} = {\mathtt{2\,427.546\: \!875}}$$

769 = 40a + (1.5a * 5)

(1.5 a * 5) = (7.5a)

769 = 40a + 7.5a

769 = 47.5a

769/47.5

$${\frac{{\mathtt{769}}}{{\mathtt{47.5}}}} = {\frac{{\mathtt{1\,538}}}{{\mathtt{95}}}} = {\mathtt{16.189\: \!473\: \!684\: \!210\: \!526\: \!3}}$$

16.189 = a

Fixededd :P

(x-1)(2x^3+2)

FOIL - First Outer Inner Last

(x * 2x^3) (x * 2) (-1 * 2x^3) (-1 * 2)

2x^4 + 2x - 2x^3 - 2

2x^4 - 2x^3 + 2x - 2

3 - 3(-2)

3 - (-6)

3 + 6

9

Your answer is 9.

I already solved this, it's -3y + 8z. Work is back on the first time you posted this problem.

Okay Anon, if you want to go back for my work, it's in the first one with this problem. The answer is 19

2x - 2y + 5z - 2x - y + 3z

Get your like variables together

(2x - 2x) (-2y - y) (+5x + 3x)

Simplify.

(0x) (-3y) (+8z)

Put it together

-3y + 8z

Huh... I got -1 from when you presented this the first time. Gimme a sec to redo.