7. Factor the polynomial by grouping. 8st+2t-20s-5 8st+2t-20s-5= (Fa

To factor the polynomial by grouping, we can group the terms in pairs and factor out the common factors from each pair.<br /><br />$8st+2t-20s-5$<br /><br />Grouping the terms in pairs:<br />$(8st+2t)-(20s+5)$<br /><br />Factoring out the common factors from each pair:<br />$2t(4s+1)-5(4s+1)$<br /><br />Now, we can factor out the common binomial factor $(4s+1)$:<br />$(4s+1)(2t-5)$<br /><br />Therefore, the factored form of the polynomial $8st+2t-20s-5$ is $(4s+1)(2t-5)$.