Step-by-step explanation:
a.
simply add both equations
x + y = 2
-3x - y = 5
----------------
-2x + 0 = 7
x = -7/2
x + y = 2
-7/2 + y = 2
y = 2 + 7/2 = 4/2 + 7/2 = 11/2
b.
1/2 x + 2y = -13
x - 4y = 8
first multiply the first equating by 2
x + 4y = -26
x - 4y = 8
--------------------
2x + 0 = -18
x = -18/2 = -9
x - 4y = 8
-9 - 4y = 8
-4y = 17
y = -17/4
Answer:
10^-5
Step-by-step explanation
Move the decimal to the right 5 places. Moving to the right makes the power a negative, moving to the left would make it a positive.
Answer:

Step-by-step explanation:
You have asked for the simpilfied form of ...

That would be ...

We suspect that's not what you meant. Parentheses are required for grouping when you write math expressions in text form. They work best using math symbols instead of words. We think you mean
... ((x -2)/(x^2 +x -6))/((x^2 +5x +4)/(x +4))
_____
Maybe you want to simplify ...

_____
<em>Comment on simplifying rational expressions</em>
Division of fractions works the same whether you're working with numbers or polynomials (or anything else). Dividing by something is the same as multiplying by its inverse (reciprocal).
(a/b)/(c/d) = (a/b)·(d/c)
I learned this as "invert and multiply". I've recently seen it referred to as "copy dot flip", meaning you copy the numerator, use a dot symbol to indicate multipication, then flip the denominator (make its reciprocal) to become what you're multiplying by.
<u>Given</u><u> </u><u>info:</u><u>-</u>If the radius of a right circular cylinder is doubled and height becomes 1/4 of the original height.
Find the ratio of the Curved Surface Areas of the new cylinder to that of the original cylinder ?
<u>Explanation</u><u>:</u><u>-</u>
Let the radius of the right circular cylinder be r units
Let the radius of the right circular cylinder be h units
Curved Surface Area of the original right circular cylinder = 2πrh sq.units ----(i)
If the radius of the right circular cylinder is doubled then the radius of the new cylinder = 2r units
The height of the new right circular cylinder
= (1/4)×h units
⇛ h/4 units
Curved Surface Area of the new cylinder
= 2π(2r)(h/4) sq.units
⇛ 4πrh/4 sq.units
⇛ πrh sq.units --------(ii)
The ratio of the Curved Surface Areas of the new cylinder to that of the original cylinder
⇛ πrh : 2πrh
⇛ πrh / 2πrh
⇛ 1/2
⇛ 1:2
Therefore the ratio = 1:2
The ratio of the Curved Surface Areas of the new cylinder to that of the original cylinder is 1:2
ABC and CBH are right angles
DBC = 90 - 37 = 53
CBJ = 90 - 31 = 59
HBD = 180 - 37 = 143
or
HBD = 31 + 53 + 59 = 143 :)