Question

1. evaluate: (+7)(−8) + (−9)(+10)
2. find the perimeter and area of this triangle.

dimensions are in meters.
12
9
6
16

Explanation:

Question 17

Step1: Multiply the first two numbers

We know that the product of a positive number and a negative number is negative. So, \((+7)(-8) = -56\)

Step2: Multiply the next two numbers

The product of a negative number and a positive number is negative. So, \((-9)(+10) = -90\)

Step3: Add the two results

Now we add \(-56\) and \(-90\). When adding two negative numbers, we add their absolute values and keep the negative sign. So, \(-56 + (-90) = - (56 + 90) = -146\)

Step1: Find the perimeter of the triangle

The perimeter of a triangle is the sum of the lengths of its three sides. The sides are \(12\) m, \(9\) m, and \(16\) m. So, perimeter \(P=12 + 9+ 16\)
\(P = 37\) meters

Step2: Find the area of the triangle

The area of a triangle is given by the formula \(A=\frac{1}{2}\times base\times height\). Here, the base is \(16\) m and the height is \(6\) m. So, \(A=\frac{1}{2}\times16\times6\)
First, \(\frac{1}{2}\times16 = 8\), then \(8\times6=48\) square meters

Answer:

\(-146\)

Question 19