Evaluate the expression 2ab3 + 6a3 - 4ab2 when a = 2 and b = 4.

a) 176
b) 180
c) 215
d) 216

Keywords:

Expression, variables, evaluate, result

For this case we have an expression with two variables, the value of each one of the variables is given in order to evaluate the expression and obtain a result. To do this, we must replace the values of a and b respectively in the given expression.

Let

and we have and , substituting the values of the variables we have:

Thus, when evaluating the expression with and we have 176.

The result is 176

Option A

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1