SOLUTION: I am struggling with these two problems: a) Which of the following is not an expression? 4r = 5; 15r + 18; 24r - 12; 18r divided by 9 b) Evaluate the expression if x=3 and

Algebra ->  Decimal-numbers -> SOLUTION: I am struggling with these two problems: a) Which of the following is not an expression? 4r = 5; 15r + 18; 24r - 12; 18r divided by 9 b) Evaluate the expression if x=3 and       Log On


   

Question 119176: I am struggling with these two problems:
a) Which of the following is not an expression? 4r = 5; 15r + 18; 24r - 12; 18r divided by 9

b) Evaluate the expression if x=3 and y = -1
6x (exponent 2) + 22xy + 20y(exponent 2)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
a)
Anything with an equal sign is an equation which is not an expression. So 4r=5 is not an expression



b)

6x%5E2%2B+22xy+%2B+20y%5E2 Start with the given expression


6%283%29%5E2%2B+22%283%29%28-1%29+%2B+20%28-1%29%5E2 Plug in x=3 and y=-1


6%289%29%2B+22%283%29%28-1%29+%2B+20%28-1%29%5E2 Square 3 to get 9


6%289%29%2B+22%283%29%28-1%29+%2B+20%281%29 Square -1 to get 1


54-66+%2B+20 Multiply


8 Combine like terms


So 6x%5E2%2B+22xy+%2B+20y%5E2=8 when x=3 and y=-1