Answer:
correct 42 in bsae 10 is 60
X-intercepts are found by factoring. Use the quadratic formula on the first since it's in standard form and you find that your x values are in fact -3 and 7. For the second one, use the Zero Product Property that says that x - 3 = 0 or x + 7 = 0. Therefore, x = 3 and -7. Signs are wrong. So not the second one. As for the third one, if you factor out a 3, your polynomial is exactly the same as the first one which did give us the desired x values. So the third one checks out. If you FOIL out the first one and then apply the quadratic formula you do get x = 3 and -7. So the fourth one checks out too. For the last one, putting it into the quadratic formula gives you x values of 3 and -7, so no to that one. Summary: 1st, 3rd, 4th have zeros of -3 and 7; 2nd and 5th do not.
X=45
We already know that one angles is 90 degrees and that the full degrees inside a triangle is 180
So minus 90 from 180 and you get 90.
Since the other two angles are congruent that means they have the same measure so divide 90 by 2 to get the measure of both angles which is your answer
To get the result we can use knowledge that reading is 2 times longer than HW.
To find this value we just have to multiply 42 times 2 so
40*2=80
Its 1 hour and 20 min - its the result
