If (5x− 4)(3x+ 7) = 15x²-ax-b, then find the value of a and b

Step-by-step explanation:

Let's start by using distributive multiplication:

So:

Grouping like terms:

Now, is equal to:

In this sense:

In order to satisfied the equality:

Hence, from (1), let's solve for a:

And from (2), let's solve for b:

Let's verify the result evaluating the values of a and b into the original equation:

As you can see, the values satisfy the equation, therefore, we can conclude they are correct.

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°