Question

Moussa tried to subtract two polynomials. his work is shown below: \begin{aligned} &\phantom{=}(t^2+6t-3)-(7t^2-4t+1) \\\\ &=t^2+6t-3-7t^2+4t-1 &\text{step }1 \\\\ &=(0-7)t^2+(6+4)t+(-3-1)&\text{step }2 \\\\ &=-7t^2+10t-4 &\text{step }3 \end{aligned} ​ =(t 2 +6t−3)−(7t 2 −4t+1) =t 2 +6t−3−7t 2 +4t−1 =(0−7)t 2 +(6+4)t+(−3−1) =−7t 2 +10t−4 ​ step 1 step 2 step 3 ​ at which step did moussa make an error, if at all

Answer 1

step Number 2 :D need any help

tell me

Answer 2

Very confusing from khan academy is though step 2