Question

упрости выражение и найди его значение:-3(2х - 1)- (-7х+4) +5(-х-30), при х=-2

Answer 1

-3*(2х-1)-(-7х+4)+5*(-х-30)
-6х+3+7х-4-5х-150
-4х-151
подставляем значение х
-4*(-2)-151=8-151=-143

Answer 2

To simplify the expression and find its value when x = -2, let's break down the given expression step by step:

Expression: -3(2x + (-1)) - (-7x + 4) + 5(-x - 30)

Step 1: Simplify the expression within the parentheses: -3(2x + (-1)) becomes -3(2x - 1). This can be further simplified as -6x + 3.

Step 2: Simplify the expression within the second set of parentheses: -(-7x + 4) becomes 7x - 4.

Step 3: Simplify the expression within the third set of parentheses: 5(-x - 30) becomes -5x - 150.

Now, let's put all the simplified expressions together:

-6x + 3 - (7x - 4) + (-5x - 150)

Step 4: Distribute the negative sign to the terms within the second set of parentheses: -6x + 3 - 7x + 4 + (-5x - 150)

Step 5: Combine like terms: -6x - 7x - 5x + 3 + 4 - 150

Step 6: Simplify further: -18x - 143

Now, to find the value of the expression when x = -2, substitute -2 for x in the simplified expression:

-18(-2) - 143 = 36 - 143 = -107

Therefore, when x = -2, the value of the given expression is -107.