Problem:
Solve
2
x
+
5
y
=
−
3
;
3
x
−
y
=
21
Steps:
I will try to solve your system of equations.
3
x
−
y
=
21
;
2
x
+
5
y
=
−
3
Step: Solve
3
x
−
y
=
21
for y:
3
x
−
y
+
−
3
x
=
21
+
−
3
x
(Add -3x to both sides)
−
y
=
−
3
x
+
21
−
y
−
1
=
−
3
x
+
21
−
1
(Divide both sides by -1)
y
=
3
x
−
21
Step: Substitute
3
x
−
21
for
y
in
2
x
+
5
y
=
−
3
:
2
x
+
5
y
=
−
3
2
x
+
5
(
3
x
−
21
)
=
−
3
17
x
−
105
=
−
3
(Simplify both sides of the equation)
17
x
−
105
+
105
=
−
3
+
105
(Add 105 to both sides)
17
x
=
102
17
x
17
=
102
17
(Divide both sides by 17)
x
=
6
Step: Substitute
6
for
x
in
y
=
3
x
−
21
:
y
=
3
x
−
21
y
=
(
3
)
(
6
)
−
21
y
=
−
3
(Simplify both sides of the equation)
Answer:
y
=
−
3
and
x
=
6
Answer:
18
Step-by-step explanation:
81π=πr^2
r= 9,-9
9+9=18
(2x+1)=Jeremy´s age
(2x+3)=Sam´s age.
we suggest this equation:
(2x+1)(2x+3)=783
4x²+6x+2x+3=783
4x²+8x-780=0
x²+2x-195=0
We solve this quadratic equation:
x=[-2⁺₋√(4-4*1*(-195))]/2=(-2⁺₋28)/2
x₁=(-2-28)/2=-15 this solution is not valid.
x₂=(-2+28)/2=13
Jeremy´s age=2x+1=2*13+1=27
Sam´s age=2x+3=2*13+3=29
Answer:
va cyclist covers a distance of 15km in 2hours calculate his speeda cyclist covers a distance of 15km in 2hours calculate his speeda cyclist covers a distance of 15km in 2hours calculate his speeda cyclist covers a distance of 15km in 2hours calculate his speeda cyclist covers a distance of 15km in 2hours calculate his speed
