X2y − 7xy + xyz + x Classify the following expression by degree and term

PLZ HELP ME ASAP PLZ PLZ PLZ!!!!! I NEED LOTS OF HELP!!! I USED 40 POINTS

cupoosta [38]

First, some defintions
reciprocals are like a/b and b/a or 5/1 and 1/5

remember, $\frac{\frac{a}{b}}{\frac{c}{d}}=(\frac{a}{b})(\frac{d}{c})=\frac{ad}{bc}$

john's fraction is reciprocal of sarah's
john=a/b
sarah=b/a

david multiplies his by sarah and gets 12/35
(b/a)(david)=12/35

multplies his number by john and gets 12/35
(a/b)(david)=15/7

hmmm

(b/a)(david)=12/35 and
(a/b)(david)=15/7

if we divide them then we do
$\frac{(\frac{b}{a})(david)}{(\frac{a}{b})(david)}=\frac{\frac{12}{35}}{\frac{15}{7}}=$
$\frac{\frac{b}{a}}{\frac{a}{b}}=\frac{\frac{12}{35}}{\frac{15}{7}}=$
$(\frac{b}{a})(\frac{b}{a})=(\frac{12}{35})(\frac{7}{15})=$
$\frac{b^2}{a^2}=\frac{84}{525}=$
$\frac{b^2}{a^2}=\frac{4}{25}$
square root both sides
$\frac{b}{a}=\frac{2}{5}$

therefor
b=2 and a=5

john's number is a/b=5/2
sarah's number is 2/5

david, hmm

sarah times david=12/35
2/5 times david=12/35
times both sides by 5/2
david=60/70
david=6/7

check other

john times david=15/7
5/2 times 6/7=15/7
30/14=15/7
15/7=15/7
true

sarah's favorite number is 2/5
john's favorite number is 5/2
david's favorite number is 6/7

6 0

3 years ago

I don't understand how to solve this, please help!

murzikaleks [220]

Answer:

x+1 , x<-1

x²-bx-4 , -1≤x≤4

1/2 x +a

substitute x=-1 , continuous everywhere

x+1=x²-bx-4 when x=-1

-1+1=-1²-b-4

then for :

x²-bx-4=1/2 x +a for x=4

4²-4b-4=1/2x+a

16-4(3)-4=4/2+a

16-12-4-2=a

the equations will be :

x+1

x²-3x-4

1/2x-2

I hope this help

7 0

3 years ago

TEN POINTS!!!!! find the equivalent exponential expression (4^3)^5

Tanya [424]

Answer:

4^15

Step-by-step explanation:

We multiply both exponents 3 and 5

So we get:

4^15

Hope this helps

Good Luck

3 0

3 years ago

A = b and c = d, then a x c = b x d<br> what kind of reasong is used here

Phoenix [80]

A = b is given to us

Multiply both sides by c to get
a = b
a*c = b*c
The rule to multiply both sides by c is the multiplicative property of equality

Then on the right side, replace c with d. This replacement is possible due to the fact that c = d. This is using the substitution property.

So we go from
a*c = b*c
to this
a*c = b*d

5 0

3 years ago

Solve the equation on the interval [0, 2pi): 12cos^2 x-9=0<br><br><br> What to do?

siniylev [52]

Answer:

$\large\boxed{x=\dfrac{\pi}{6}\ \vee\ x=\dfrac{5\pi}{6}\ \vee\ x=\dfrac{7\pi}{6}\ \vee\ x=\dfrac{11\pi}{6}}$

Step-by-step explanation:

$12\cos^2x-9=0\qquad\text{add 9 to both sides}\\\\12\cos^2x=9\qquad\text{divide both sides by 12}\\\\\cos^2x=\dfrac{9}{12}\\\\\cos^2x=\dfrac{9:3}{12:3}\\\\\cos^2x=\dfrac{3}{4}\to\cos x=\pm\sqrt{\dfrac{3}{4}}\\\\\cos x=\pm\dfrac{\sqrt3}{2}\\\\\text{Look at the picture}\\\\x=\dfrac{\pi}{6}\ \vee\ x=\dfrac{5\pi}{6}\ \vee\ x=\dfrac{7\pi}{6}\ \vee\ x=\dfrac{11\pi}{6}$

6 0

3 years ago