(b) 6x-7 y = 25
15x+3y = 42

x=3

y= -1

Step-by-step explanation:

with 1 equation you can solve for 1 variable. With 2 equations you can solve for 2 variables. This is solvable.

6x-7y = 25

15x+3y = 42

first simplify to make easier to work with

6x-7y = 25 can not be factored further

15x+3y = 42 can be divided by 3 on both sides

5x+y = 14

then you have

6x-7y = 25

5x+y = 14

solve by substitution:

isolate y in second equation

5x+y = 14 >    y= 14-5x

put y into first equation

6x-7(14-5x) = 25

6x- 98 --35x =25

6x- 98 +35x =25

41x =123

x=3

to get y, substitute x into equation

5x+y = 14

5(3) +y=14

15+y=14

y=-1

hope this helps !

"standard form:

3x2 + 14x − 10 = 0

solutions based on quadratic formula:

x1   = −14 − √ 142 − 4×3×(−10) /   2×3   = −14 − 2 × √ 79 /   6   ≈ −5.296

x2   = −14 + √ 142 − 4×3×(−10) /   2×3   = −14 + 2 × √ 79 /   6   ≈ 0.629

c

step-by-step explanation: