Without drawing the graph, find out whether the lines representing the following pair of linear equations intersect at a point, are parallel or coincident: 9x-10y=21 & 3/2x-5/3y=7/2

The easiest way to solve this question is to write out both equations in the form y = mx + c, where m is the gradient and c is the y-intercept.

a) Thus, if we start with 9x - 10y = 21, then we get:

9x - 10y = 21

(9/10)x - y = 21/10 (Divide both sides by 10)

(9/10)x = y + 21/10 (Add y to both sides)

(9/10)x - 21/10 = y (Subtract 21/10 from both sides)

Thus, our first equation may be written as y = (9/10)x - 21/10

b) Now if we take the second equation, (3/2)x - (5/3)y = 7/2, we can follow the same process to get:

(3/2)x - (5/3)y = 7/2

(9/10)x - y = 21/10 (Multiply each side by 3/5)

(9/10)x = y + 21/10 (Add y to each side)

(9/10)x - 21/10 = y (Subtract 21/10 both sides)

Thus, the second equation may be written as y = (9/10)x - 21/10.

Now you might have already realised this but the two equations are actually exactly the same; if they are the same line then they are said to be coincident.

Note that if the two lines are parallel, then their gradients (m) would be the same, but the y-intercepts (c) would be different (eg. y = 2x + 3 and y = 2x + 4 are parallel).

If they just intersect at a point, then the gradients of the lines would be different, but the y-intercepts could be the same or different (eg. y = 4x + 2 and y = 9x + 2 intersect at one point).

For them to be coincident however, both the gradient and y-intercept must be the same as only then would they be the same line.

answer: there are x+184 pages in olivia's book.

step-by-step explanation:

let the total number of pages in the book which olive has already read be x.

then if olive has 184 pages left to read, then the total number of pages are in olive's book= pages she has read+pages she has left to read

therefore, the total number of pages in olivia's book=

hence, there are x+184 pages in olivia's book.