Solve the system of equations. 3x + 4y + 3z = 5
2x + 2y + 3z = 5
5x+ 6y+7z = 7
a. (x = 13, y=-6, z = -2)
b. (x = 15, y = -8, z = -4)
c. (x = 16, y = -9, z = -1)
d. (x = 14, y = -7, z = 3)

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

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

good job you smart son of a gun you are smarter that einstein. 7