Question Number 116259 by Khalmohmmad last updated on 02/Oct/20
Answered by TANMAY PANACEA last updated on 02/Oct/20
$${a}+{a}+\mathrm{4}{d}=\mathrm{30}\:\:{considering}\:{A}.{P}\:{series} \\ $$$${a}+\mathrm{2}{d}+{a}+\mathrm{6}{d}=\mathrm{120} \\ $$$$\mathrm{8}{d}+\mathrm{30}−\mathrm{4}{d}=\mathrm{120} \\ $$$${d}=\frac{\mathrm{90}}{\mathrm{4}}=\frac{\mathrm{45}}{\mathrm{2}} \\ $$$$\mathrm{2}{a}+\mathrm{90}=\mathrm{30} \\ $$$${a}=−\mathrm{30} \\ $$$${a}_{\mathrm{1}} ={a}=−\mathrm{30} \\ $$