I really hate Math.. My teacher doesn't explain it... So need help to solve this all?? PLS....?

Question

A rectangle garden w/ dimensions 18 x 24 m is to have a side walk of uniform width place completely around the inside of its border in such a way that the area of the remaining garden is 216 sq. m. How wide is the side?

Two planes start from Baguio at the same time and fly in opposite direction, one averaging a speed of 40mi/hr. greater than the other. If they are 2000 mi. apart after 5 hours, find their average speed.

The square of 2 more than a no. is the same as 4 less than 10 times the no. Find the no's

Mary is 15 yrs. older than her sister Jane. Six years ago Mary was six times as old as Jane. Find their present ages.

(SITE OF EXAMPLE OF THIS LAST 2 QUESTION I WILL SOLVE IT MYSELF)

Answer 1

Let the width of the sidewalk,in meters, be x. The dimensions of the remaining garden are 18-2x and 24-2x.

Since the area must be 216, x must satisfy the equation

(18-2x)(24-2x) = 216.

Multiply it out:

432-84x+4x^2 =216.

Divide by 4:
x^2-21x+108=54

Put everything on one side:
x^2-21x+54=0.

Factor:
(x-18)(x-3)=0

So x=18m or x=3m. 18m doesn't make sense, because then the garden would have negative dimensions. So x=3m is the width of the sidewalk.

Second problem:

Let x be the speed of the faster plane, in mph. Then the distance it travels is speed*time = 5x.

The distance the other plane travels in the same time is 5(x-40).

Since they're traveling in opposite directions, the distance between them is 5x+5(x-40) = 10x-200.

This distance is 2000 mi, so you solve

10x-200=2000

or 10x=2200, and get x=220. That's the speed of the faster plane; the other plane's speed is 180.

Answer 2

I got 3 m on the first one. Is that right?

vertically
3
12
3

so that total height is 18

horizontally
3
18
3

so total width of entire enclosure is 24

To answer this question, you have to know how big the inside enclosure is. You have the square, but not the dimensions. To get the dimensions, I just decreased the 18 by 1 and the 24 by 1. I did this each time until multiplying the two came to 216. It would have been aweful if it turned out to be some fractional number, but it didn't. Subtract new garden width by previous garden width and you'll get the width of the sidewalk.

no time for second problem now, sorry

Answer 3

properly, somewhat some human beings conflict with math, and then whilst they get undesirable on the tests or assignments, they don't prefer to be considered as stupid, so they simply say that they are instructor's poor. There are additionally scholars who're not so stable on the problem, and have genuinely no force to realize any extra than they are, so whilst the instructor provides them extra homework, or shop them after classification to assist them etc, they locate it annoying, and consequently say the instructor's recommend and unreasonable for protecting them after classification etc. As for the human beings wishing you undesirable success on contests etc, they simply maximum possibly do not comprehend math the style you do. you will possibly even see it as relaxing, yet they see it as confusing, and because they have not got a skills for math, and it takes them an prolonged time to hold close an thought, they hate you for with the ability to comprehend some thing with out postpone. properly perhaps not hate, yet they are jealous/offended approximately it. additionally, on account that they have genuinely no interest in math and picture of it as uninteresting, they think of the want arises be "nerdy" in case you definitely like the problem. fortunate for me, at my college grades and issues do not count extensive style that lots, and to maximum human beings, over-accomplishing is a few thing to applaud as a exchange of a few thing to be frowned upon.....