Pythagorean theorem
c2 = a2 + b2
71^2 = 43^2 + b2
5041 = 1849 + b2
3192 = b2
b = 56.5 which is answer choice d
Answer:
Ok here
Step-by-step explanation:

To find the gradient of the tangent, we must first differentiate the function.

The gradient at x = 0 is given by evaluating f'(0).

The derivative of the function at this point is negative, which tells us <em>the function is decreasing at that point</em>.
The tangent to the line is a straight line, so we will have a linear equation of the form y = mx + c. We know the gradient, m, is equal to -1, so

Now we need to substitute a point on the tangent into this equation to find c. We know a point when x = 0 lies on here. To find the y-coordinate of this point we need to evaluate f(0).

So the point (0, -1) lies on the tangent. Substituting into the tangent equation:
His father can drive 25 days without the warning light
Answer:
25
Step-by-step explanation:
25 has 2 digits
25 is less than 30
25 is odd
2+5 = 7
It is 25.