Moussa tried to subtract two polynomials. his work is shown below: \begin{aligned} & \phantom{=}(t^2+6t--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