Answer:
Step-by-step explanation:
Move 729 to the left side of the equation by subtracting it from both sides. x 3 − 729 = 0 Factor the left side of the equation. Rewrite 729 as 9
3
. x
3
−
9
3
=
0
. Since both terms are perfect cubes, factor using the difference of cubes formula, a
3
−
b
3
=
(
a
−
b
)
(
a
2+ab+b2). Where a
=x and b=9. (x−9)(x2+x⋅9+92)=0
. Simplify. Move 9 to the left of x
. (x−9)(x2+9x+92)=0. Raise 9 to the power of 2
. (x
−9
)(
x
2
+
9
x
+81
)=0
. Set x
−9 equal to 0 and solve for x. Set the factor equal to 0. x−
9=
0. Add 9 to both sides of the equation. x=9
. Set x2+
9
x
+
81 equal to 0 and solve for x
. Set the factor equal to 0
. x2+9x+81=0. Use the quadratic formula to find the solutions. −b±√b2−4(ac) 2a. Substitute the values a=1, b=9, and c=81 into the quadratic formula and solve for x. −9±√92−4⋅ (1⋅81
) 2⋅
1 Simplify. Simplify the numerator. Raise 9 to the power of 2. x=−9±√81−4⋅(1⋅81) 2⋅1. Multiply
81
by
1
.
x
=
−
9
±
√
81
−
4
⋅
81
2
⋅
1
Multiply
−
4
by
81
.
x
=
−
9
±
√
81
−
324
2
⋅
1
Subtract
324
from
81
.
x
=
−
9
±
√
−
243
2
⋅
1
Rewrite
−
243
as
−
1
(
243
)
.
x
=
−
9
±
√
−
1
⋅
243
2
⋅
1
Rewrite
√
−
1
(
243
)
as
√
−
1
⋅
√
243
.
x
=
−
9
±
√
−
1
⋅
√
243
2
⋅
1
Rewrite
√
−
1
as
i
.
x
=
−
9
±
i
⋅
√
243
2
⋅
1
Rewrite
243
as
9
2
⋅
3
.
Tap for fewer steps...
Factor
81
out of
243
.
x
=
−
9
±
i
⋅
√
81
(
3
)
2
⋅
1
Rewrite
81
as
9
2
.
x
=
−
9
±
i
⋅
√
9
2
⋅
3
2
⋅
1
Pull terms out from under the radical.
x
=
−
9
±
i
⋅
(
9
√
3
)
2
⋅
1
Move
9
to the left of
i
.
x
=
−
9
±
9
i
√
3
2
⋅
1
Multiply
2
by
1
.
x
=
−
9
±
9
i
√
3
2
Factor
−
1
out of
−
9
±
9
i
√
3
.
x
=
−
1
9
±
9
i
√
3
2
Multiply
−
1
by
−
1
.
x
=
1
−
9
±
9
i
√
3
2
Multiply
−
9
±
9
i
√
3
by
1
.
x
=
−
9
±
9
i
√
3
2
The final answer is the combination of both solutions.
x
=
−
9
−
9
i
√
3
2
,
−
9
+
9
i
√
3
2
The solution is the result of
x
−
9
=
0
and
x
2
+
9
x
+
81
=
0
.
x
=
9
,
−
9
−
9
i
√
3
2
,
−
9
+
i
√
3
2
The stock of cat food will last for 149 weeks.
Step-by-step explanation:
Given,
Bags of cat food in stock = 112
Bags used each week = 
Let,
x be the number of weeks.
Therefore,
Multiplying both sides by 4/3
Rounding off to nearest whole number;
x=149
The stock of cat food will last for 149 weeks.
Keywords: fraction, multiplication
Learn more about fractions at:
#LearnwithBrainly
Let the total be x
1/6x=3
x/6=3
x=18
therefore Ramal's stamp has 18 pages
5+3=8
Every time you draw, its minus one from denominator
1st marble red: 5/8
2nd marble green: 3/7
Answer:
27 miles in the morning and 85 miles in the afternoon.
Explanation:
Let m be the number of miles they rode in the morning. They rode 4 more than 3 times this many in the afternoon; this gives us the expression
3m+4
to represent the miles ridden in the afternoon.
Together they rode 112 miles; this means we add the morning miles, m, to the afternoon miles, 3m+4, and get 112:
m+3m+4 = 112
Combine like terms:
4m+4 = 112
Subtract 4 from each side:
4m+4-4= 112-4
4m = 108
Divide both sides by 4:
4m/4 = 108/4
m = 27
They rode 27 miles in the morning.
That means in the afternoon, they rode
3m+4 = 3(27)+4 = 81+4 = 85 miles.
