Acollection of nickels and dimes is worth $6.10. there are 67 coins in all. how many nickels are there? 12 18 49 55

A. 12

Step-by-step explanation:

Let d represent the number of dimes and n represent the number of nickel.

We have been given that a collection of coins has 67 coins in all. This means that total number of nickels and dimes is 67. We can represent this information in an equation as:

Since we know that a dime is worth $0.10, so d dimes will be worth 0.10d.  A nickel is worth $0.05, so n nickels will be worth 0.05n.

We are also told that the collection is worth $6.10. We can represent this information in an equation as:

We will use substitution method to solve system of linear equations.

From equation (1) we will get,

Upon substituting in equation (2) we will get,

Let us divide both sides of our equation by .

Therefore, there are 12 nickels in the collection and option A is the correct choice.

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!

y = 3x+4

step-by-step explanation:

to find the slope

slope = (y2-y1)/ (x2-x1)

    = (-8-4)/ (-4-0)

    = -12/-4

  = 3

using the slope intercept form of a line

y= mx+b

we know the slope is 3

we know the y intercept is 4 ( the point where it crosses the y axis or x=0)

y = 3x+4