Answer:
in which standard u are ???
Step-by-step explanation:
And of which subject is this ques is???
Answer:
i) True
ii) True
Step-by-step explanation:
<u>Given :-</u>
Point (-1, 2)
<u>To Find :</u>
Whether the point is a solution of :
- y = -2x
- y = x + 3
<u>Solving :-</u>
Substitute the value of the point in each of the equations.
=> y = -2x
=> 2 = -2(-1)
=> 2 = 2 [∴ The point makes it true]
=> y = x + 3
=> 2 = -1 + 3
=> 2 = 2 [∴ The point makes it true]
x^2 = 16/100
We must solve for x by taking the square root of both sides.
But imagine x^2 = 9. x = 3 is a solution because 3^2 = 9. But x = -3 is also a solution because (-3)^2 = 9. So we need to add the plus and minus sign to account for all of our solutions.
√x^2 = √(16/100)
We square root both sides to remove the exponent 2 on x. Then
x = ±√(16/100)
Then we have to use a Property of Radicals which is √(x/y) = √(x) / √(y).
Then the square root of 16 is 4 and the square root of 100 is 10. 4/10 is 2/5 simplified.
Answer:
x = 14
y = -7
z = -3
but this is none of the provided answer options !
Step-by-step explanation:
it's really easy by principle. it's just some work to do.
we try to find equations to express one variable in terms of the others.
but one thing there is : your teacher made a mistake.
the right solution is x = 14, y = -7, z = -3
your teacher made a typo at d.
but the right answer should be d.
just to give you an idea how this can be done (and also to prove that there is a mistake by the teacher):
we can directly try to transform one expression into one that describes x by y and z.
and then another to describe e.g. z by y. and then solve the third one just for y. and then we get the other 2 by these other expressions.
or we can e.g. add or subtract one equation to/from another. this is one of these cases, because we can find really simple expressions that way :
we do
5x + 6y + 7z = 7
- (3x + 4y + 3z = 5)
- (2x + 2y + 3z = 5)
---------------------------
0x + 0y + z = -3
=> z = -3
3x + 4y - 3×3 = 5
3x = -4y + 14
x = (-4y + 14)/3
2×(-4y + 14)/3 + 2y - 9 = 5
(-8y + 28)/3 + 2y = 14
-8y + 28 + 6y = 42
-2y = 14
y = -7
x = (-4×-7 + 14)/3 = (28+14)/3 = 42/3 = 14
My best guess is c= 4.20h
Sorry if I’m wrong