6 x = -3 + 7 x = 4 Solve for x Start at the origin Negative moves to the leftPositive moved to the rightx =x = 4
7 x = -2 - 7 x = -2 + - 7 x = -9 Solve for x Start at the origin Negative moves to the leftPositive moved to the rightx =x =x = -9
8 x = -2 - -7 x = -2 + 7 x = 5 Solve for x Start at the origin Subtraction is the addition of the opposite signNegative to the leftPositive to the rightx =x =x = 5
9 Adding and Subtracting Addition does not change the sign of a numberExample: = x = x5 = x = xSubtraction is the addition of the opposite signExample: – 3 = x = x= x = x-1 = x 1 = x
10 Multiply and Divide If the signs are the same (both positive or both negative),the answer will be positive.+ * + = * - = +If the signs are different(one positive and one negative),the answer will be negative.+ * - = * + = -
11 Multiply and DivideTwo like signs make a positive sign. Two unlike signs make a negative sign.
12 ExampleSolve for x.Subtraction signNegative signx = 18 – (–16) – 3 – (–5) + 2 = – = (–3) = 41 + (–3) [I added all the positive numbers.] = 41 – 3 [The addition of a negative is the same as the subtraction of a positive.] = 38