Answer:
Mistake in Line 2
Step-by-step explanation:
Line 1
7(6) ÷ 5 + 42
Line 2
7(6) ÷ 5 + 16
Line 3
42 ÷ 5 + 16
Line 4
42 ÷ 21
Line 5
2
To simplify any expression we use order of operation
Line 1 is 7(6) ÷ 5 + 42
Order of operation is PEMDAS
First we start with parenthesis
so we multiply 7(6) in line 2
7*6- 42
So Line 2 is 42 ÷ 5 + 42
Hence there is a mistake in Line 2
He practiced for 1 hour and 30 minutes
Answer:
Yes because there are no repeated dependent variables.
Step-by-step explanation:
2x^2 + 3xy - 4y^2 when x = 2 and y = -4
= 2(2)^2 + 3(2)(-4) - 4(-4)^2 = 2(4) + (-24) - 4(16) = 8 - 24 - 64 = -80
