\frac{ d }{ 2 } { 101 }^{ 2 } + \left( { a }_{ 1 } - \frac{ d }{ 2 } \right) (101) = 2020
Solve for a_1
a_{1}=20-50d
Solve for d
d=-\frac{a_{1}}{50}+\frac{2}{5}
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d\times 101^{2}+2\left(a_{1}-\frac{d}{2}\right)\times 101=4040
Multiply both sides of the equation by 2.
d\times 10201+2\left(a_{1}-\frac{d}{2}\right)\times 101=4040
Calculate 101 to the power of 2 and get 10201.
d\times 10201+202\left(a_{1}-\frac{d}{2}\right)=4040
Multiply 2 and 101 to get 202.
d\times 10201+202a_{1}+202\left(-\frac{d}{2}\right)=4040
Use the distributive property to multiply 202 by a_{1}-\frac{d}{2}.
d\times 10201+202a_{1}-101d=4040
Cancel out 2, the greatest common factor in 202 and 2.
10100d+202a_{1}=4040
Combine d\times 10201 and -101d to get 10100d.
202a_{1}=4040-10100d
Subtract 10100d from both sides.
\frac{202a_{1}}{202}=\frac{4040-10100d}{202}
Divide both sides by 202.
a_{1}=\frac{4040-10100d}{202}
Dividing by 202 undoes the multiplication by 202.
a_{1}=20-50d
Divide 4040-10100d by 202.
d\times 101^{2}+2\left(a_{1}-\frac{d}{2}\right)\times 101=4040
Multiply both sides of the equation by 2.
d\times 10201+2\left(a_{1}-\frac{d}{2}\right)\times 101=4040
Calculate 101 to the power of 2 and get 10201.
d\times 10201+202\left(a_{1}-\frac{d}{2}\right)=4040
Multiply 2 and 101 to get 202.
d\times 10201+202a_{1}+202\left(-\frac{d}{2}\right)=4040
Use the distributive property to multiply 202 by a_{1}-\frac{d}{2}.
d\times 10201+202a_{1}-101d=4040
Cancel out 2, the greatest common factor in 202 and 2.
10100d+202a_{1}=4040
Combine d\times 10201 and -101d to get 10100d.
10100d=4040-202a_{1}
Subtract 202a_{1} from both sides.
\frac{10100d}{10100}=\frac{4040-202a_{1}}{10100}
Divide both sides by 10100.
d=\frac{4040-202a_{1}}{10100}
Dividing by 10100 undoes the multiplication by 10100.
d=-\frac{a_{1}}{50}+\frac{2}{5}
Divide 4040-202a_{1} by 10100.
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Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
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Limits
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