Evaluate the algebraic expression “2a (a – 2b)” when a = 2 and b = -5.

48

Concept:

Here, we need to understand the idea of evaluation.  

When encountering questions that gave you an expression with variables, then stated: "If x = a, y = b, z = c" (a, b, c are all constants), this means you should substitute the value given for each variable back to the expression.

Solve:

Given information

a = 2

b = -5

Given expression

2a (a - 2b)

Substitute values into the expression

=2 (2) ((2) - 2 (-5))

Simplify by multiplication

=4 (2 - (-10))

=4 (2 + 10)

Simplify by addition

=4 (12)

Simplify by multiplication

=

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walter needs to make at least 5 more cookies but no more than 40. 5 ≥ x ≥ 40;

step-by-step explanation:

walter has to make a minimum of 20 cookies. he already has 15 cookies made, so he must make 5 more to meet the minimum.

the maximum amount of cookies he can make is 55. he already has 15, so he has to make no more than 40 more cookies to meet the maximum.

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58