The difference of c and 10 A. c+10 B. 10c C.10divide c D. c-10

Can someone write this in standard form -7-3x=9x(x+2)

lbvjy [14]

-7 - 3x = 9x(x + 2)

Standard Form:
-9x^2 - 21x - 7 = 0

8 0

3 years ago

Read 2 more answers

If the cost of a notebook is 2x-3 and the cost of a pen is x-4, what is the cost of 3 notebooks and 5 pens?

AlekseyPX

Answer:

notebook=3 pen =1

Step-by-step explanation:

plug in the numbers in the equation. 2(3)-3 2*3=6 6-3=3

(5)-4=1

7 0

3 years ago

A radioactive substance decays according to the following function, where yo is the initial amount present, and y is the amount

antoniya [11.8K]

Answer:

Therefore 10.75 days is the half life of the given radioactive substance.

Step-by-step explanation:

Given that, a radioactive substance decays function is

$y=y_0 \ e^{-0.0645t}$

where y₀= initial amount of radioactive substance

y= The amount of radioactive substance at time t.

t is in days

Half life is the time required to reduce the amount of the substance to its half of the initial amount.

For half life

$y=\frac{1}{2} y_0$

Putting the value of y in the given function

$\frac12y_0=y_0 \ e^{-0.0645t}$

$\Rightarrow \frac12= \ e^{-0.0645t}$

Taking ln both sides

$\Rightarrow ln( \frac12)= ln(e^{-0.0645t})$

$\Rightarrow ln1-ln2=-0.0645t$ [ $\because lne^a=a,$ $ln(\frac ab)= ln \ a- ln \ b$ ]

$\Rightarrow-ln2=-0.0645t$

$\Rightarrow t=\frac{-ln2}{-0.0645}$

=10.75 days.

Therefore 10.75 days is the half life of the given radioactive substance.

8 0

3 years ago

25x + 22x + 9 = 180.......

Alina [70]

$\sf\purple{The\:value\:of\:x\:is\:3.638.}$ ✅

Step-by-step explanation:-

$25x + 22x + 9 = 180 \\ ⇢ 47x = 180 - 9 \\ ⇢ 47x = 171 \\ ⇢ x = \frac{171}{47} \\ ⇢ x = 3.638$

To verify:-

$25 \times 3.638 + 22 \times 3.638 + 9 = 180 \\ ⇢ 90.95 + 80.036 + 9 = 180 \\ ⇢ 180 = 180 \\ ⇢ L.H.S.=R. H. S$

Hence verified. ✔

$\huge{\textbf{\textsf{{\orange{My}}{\blue{st}}{\pink{iq}}{\purple{ue}}{\red{35}}{\green{♡}}}}}$

4 0

3 years ago

Sam sold half of his comic books and then brought seven more. He now has twelve. how many did he began with?

aleksley [76]

Answer:

He began with 10 comic books

Step-by-step explanation:

12 - 7 - 10 comic books he started out with

10 ÷ 2 = 5

5 left after he sold half of his comic books

5 + 7 = 12 comic books after he brought seven more

Hope this helps!

7 0

2 years ago

Read 2 more answers