Variables: 3140

Determine the value of the expression 3a + 2b - a² - 4b² for the values ​​of the variables:
a) a = - 1, b = 3
b) a = 2, b = -1
c) a = -2, b = -3
d) a = 4, b = 2
e) a = -5, b = 0

Correct answer:

A =  -34
B =  -4
C =  -52
D =  -16
E =  -40

Step-by-step explanation:

$$\begin{gathered} a=-1 \\ b=3 \\ A=3\cdot a+2\cdot b-a^2-4\cdot b^2=3\cdot (-1)+2\cdot 3-(-1{)}^2-4\cdot 3^2=-34 \end{gathered}$$

$$\begin{gathered} a=2 \\ b=-1 \\ B=3\cdot a+2\cdot b-a^2-4\cdot b^2=3\cdot 2+2\cdot (-1)-2^2-4\cdot (-1{)}^2=-4 \end{gathered}$$

$$\begin{gathered} a=-2 \\ b=-3 \\ C=3\cdot a+2\cdot b-a^2-4\cdot b^2=3\cdot (-2)+2\cdot (-3)-(-2{)}^2-4\cdot (-3{)}^2=-52 \end{gathered}$$

$$\begin{gathered} a=4 \\ b=2 \\ D=3\cdot a+2\cdot b-a^2-4\cdot b^2=3\cdot 4+2\cdot 2-4^2-4\cdot 2^2=-16 \end{gathered}$$

$$\begin{gathered} a=-5 \\ b=0 \\ E=3\cdot a+2\cdot b-a^2-4\cdot b^2=3\cdot (-5)+2\cdot 0-(-5{)}^2-4\cdot 0^2=-40 \end{gathered}$$

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