Question

what are the x-intercepts of y=-2(x-7)(x=2)

Answer 1

you mean \[y=-2(x-7)(x+2)\]
??
to find x-intercept, you just plug in y=0
\[-2(x-7)(x+2)=0\]
can you get 2 values of 'x' from here ?

Answer 2

by the way,
\(\huge \color{red}{\text{Welcome to Open Study}}\ddot\smile\)

Answer 3

do i use the distributive property for the -2(x-7) and then go from there??

Answer 4

not required,
if you have b(x-a) =0, you can directly take x=a.
example :
4(x+10)(x-22) will give you
x+10 =0, x-22 =0
x=-10,22
so what about
-2(x-7)(x+2)=0
?

Answer 5

so would x=-7,2 ??

Answer 6

see,
for x-a = 0, x=a
for x+c=0, x=-b
so, try again with
-2(x-7)(x+2)=0

Answer 7

*for x+c=0, x=-c

Answer 8

ohh ok so x=-7,-2

Answer 9

\[(x-7)=0 \implies x=7 \\ (x+2)=0 \implies x=-2

\\ intercepts : (7,0),(-2,0)\]

Answer 10

ohh ok lol i get it i just didnt see that it was a -7 i thought it was positve:P thank u!!

Answer 11

welcome ^_^
just to clarify, if the question has x+2 ---> -2,0
if the question has x-2 ---> 2,0

Answer 12

yup! and what is the point of the -2 in the begining? does it have anything to do with what they are asking?

Answer 13

for finding x intercept, it doesn't matter.
f(x) = a(x-7)(x+2) will have same intercepts, whatever a may be.

Answer 14

same 'x' intercepts.
'y' intercepts will be different....

Answer 15

ok thank u!! could u also answer another question i have on a different algebra subject?

Answer 16

sure, ask :)

Answer 17

what is the real part of the standard form of the expression (4-i)(2+3i) ??

Answer 18

can you foil ?

Answer 19

yes

Answer 20

do it here.
do you know what 'i' is or what i=... ?

Answer 21

sadly nope

Answer 22

i is the imaginary number , i=\[\sqrt{-1}\].
so , \[i^2=... ?\]

Answer 23

im not sure..

Answer 24

\[i=\sqrt{-1} \implies i^2=-1\]
now tell me what you get after foiling ?

Answer 25

in the equation?

Answer 26

in the equaion it would be 8+12i-2i+2i^2

Answer 27

i'll write down steps, see if you understand.
\[(4-i)(2+3i) =8+10i-3i^2 \\ but, i^2=-1 \\ =8+10i+3=11+10i\]
now, real part of a+bi =a
so, real part of 11+10 i=11

Answer 28

ask if any doubts anywhere.

Answer 29

were did the 10,3 and 11 come from:P

Answer 30

8+12i-2i+2i^2---->you didn't foil correctly
8+12i-2i-3i^2
= 8+ 10 i -3(-1)
got this ?

Answer 31

-i * +3i = -3i^2

Answer 32

ohh yup i got it

Answer 33

now any more doubts on how real part = 11 ?

Answer 34

nope i got it!

Answer 35

good to hear , glad to help :)

Answer 36

thank u! i really like this website! im glad i found it!!