Please Help!! I need help solving word problems
I have a lot troubles understanding word problems on where to start the solving process. Please help I need answers by tomorrow please show all work to help me understand the how.
1. In solving the equation (x + 1)(x – 2) = 54, Eric stated that the solution would be
x + 1 = 54 => x = 53 or (x – 2) = 54 => x = 56
However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to understand better; solve the problem yourself, and explain your reasoning.
2. If a stone is tossed from the top of a 190 meter building, the height of the stone as a function of time is given by h(t)=-9.8t^2-10t+190, where t is in seconds, and height is in meters. After how many seconds will the stone hit the ground? Round to the nearest hundredth’s place; include units in your answer.
3. Use the discriminant to determine whether the following equations have solutions that are: two different rational solutions; two different irrational solutions; exactly one rational solution; or two different imaginary solutions.
a)Two different irrational solutions
b)Two different imaginary solutions
c)Exactly one rational solution
d)Two different rational solutions
4. Solve using the substitution method. Show your work. If the system has no solution or an infinite number of solutions, state this.
18x + 6y = 78
12x + 54y = -48
5. Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.
-4x-14y = 42