the sum of first three terms in an Ap is 24 and the sum of their squares is 224 .find the first three terms of AP. ( solve stp by stp and in a paper) YOU WILL BE A BRAN LIST IF YOU ANSWER
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Let the first three terms be ( a - d ), a ( a+ d ).
3a - d + d = 24
a = 24 / 3 = 8
Sum of their square = 224
( a - d ) ^2 + a^2 + ( a + d ) ^2 = 224
a^2 + d^2 - 2ad +a^2 +a^2 + d^2 - 2ad = 224
3a^2 + 2d^2 = 224
3 ( 8 ) ^2 + 2d^2 = 224
64 × 3 + 2d^2 = 224
192 + 2d^2 = 224
2d^2 = 224 - 192
2 d^2 = 32
d^2 = 32 / 2 = 16
d = 4
First term = a = 8
Second term = a +d = 8 +4 = 12
Third term = a + 2d = 8 + 8 = 16
3a - d + d = 24
a = 24 / 3 = 8
Sum of their square = 224
( a - d ) ^2 + a^2 + ( a + d ) ^2 = 224
a^2 + d^2 - 2ad +a^2 +a^2 + d^2 - 2ad = 224
3a^2 + 2d^2 = 224
3 ( 8 ) ^2 + 2d^2 = 224
64 × 3 + 2d^2 = 224
192 + 2d^2 = 224
2d^2 = 224 - 192
2 d^2 = 32
d^2 = 32 / 2 = 16
d = 4
First term = a = 8
Second term = a +d = 8 +4 = 12
Third term = a + 2d = 8 + 8 = 16
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first term is 8
second term is 12
third term is 16
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