Question

3. Обчисліть зручним способом: a) (-2) (-64) • (-5)= б) (-25) • 78 • (-4) = в) -1,25 • (-20) • (-8) • (-5) =

Answer 1

Ответ:

а)(-2)(-64)(-5)=-2•-64•-5=-640

Answer 2

a) (-2) (-64) • (-5) = 640

To calculate this expression, we multiply the numbers together. The negative signs can be handled by remembering the rule that states when you multiply two negative numbers, the result is positive.

(-2) (-64) • (-5) = (2 * 64) • (-5) = 128 • (-5) = -640

Therefore, (-2) (-64) • (-5) equals 640.

b) (-25) • 78 • (-4) = 7800

Similarly, we multiply the numbers together, considering the negative signs.

(-25) • 78 • (-4) = (-25) • (-4) • 78 = 100 • 78 = 7800

Therefore, (-25) • 78 • (-4) equals 7800.

c) -1.25 • (-20) • (-8) • (-5) = -1000

Again, multiply the numbers together, taking into account the negative signs.

-1.25 • (-20) • (-8) • (-5) = 1.25 • 20 • 8 • 5 = 250 • 8 • 5 = 2000 • 5 = -1000

Therefore, -1.25 • (-20) • (-8) • (-5) equals -1000.