Question

f(-7)=4(-7)^2+8(-7)-5
help! i have forgotten the basic algebra rules...

Answer 1

f(-7)-135=0

Answer 2

the answer should be 135, according to mathlab. i don't get that.

Answer 3

4(-7)^2+8(-7)-5

4(49) - 56 - 5
196 - 56 - 5
191 - 56
=135

Answer 4

dealing with functions.. f(z)=4z^2+8z-5, when input is -7

Answer 5

f(-7)=4(-7)^2+8(-7)-5

here, exponents happen first so,
f(-7)=4*49+8(-7)-5
then multiplication (and division)
f(-7)=196-56-5


eh, lgbasallote types faster than me. :)

Answer 6

hahaha :))) good game ^_^

Answer 7

just one question: how does 4(-7)^2 become positive 196?

Answer 8

4(49)

Answer 9

exponents are done first in the order of operations. Then the multiplication by 4

Answer 10

Order:

( )
exponents
* and /
+ and -

etc. etc.

Answer 11

yes, understood, so the
neg squared becomes pos. My calculator confused me, as it shows -49.

Answer 12

try putting the ( ) around the -7 when you put it to the power.

Answer 13

so, type in ( -7 ) ^2

Answer 14

Ok! Thx to both of you for your help:)

Answer 15

welcome :)