We have an isosceles triangle;
A=opposite angle side a.
B=opposite angle side b.
C=opposite angle side c.

A=B
Method 1:

We can divide the isosceles triangle in two right triangles,
hypotenuse=7
side=9/2=4.5

B=A=arccossine (4.5/7)=49.994799...º≈50º
C/2=90º-50º=40º ⇒ C=2*40º=80º

Answer:
a=7; A=50º
b=7; B=50º
c=9; C=80º

Method 2:
Law of cosines:
a²=b²+c²-2bcCosA ⇒CosA=(a²-b²-c²)/(-2bc)
CosA=(49-49-81) / (-126)=0.642857
A=arco cos (81/126)≈50º

B=A=50º

A+B+C=180º
50º+50º+C=180º
C=180º-100º
C=80º

Answer:

a=7; A=50º
b=7; B=50º
c=9; C=80º

8 0

3 years ago

L33. Solve 41x - 7 + 12 = 28 Solution(s).

s2008m [1.1K]

Answer:

41x-7+12=28

41x+5=28

41x=28-5

41x= 23

x= 23/41

x= 0.56

7 0

3 years ago

Which pair of expressions is equivalent using the Associative Property of Multiplication? (3 points) 5(3a ⋅ 4) = 15a ⋅ 20 5(3a ⋅

cluponka [151]

Answer:

5(3a ⋅ 4) = (5 ⋅ 3a) ⋅ 4

Step-by-step explanation:

The Associative Property is applied to two types of operations: addition and multiplication. This property indicates that, when there are three or more terms in these operations, the result does not depend on the way in which the terms are grouped.

In this sense, the associative property for the sum is mathematically given by:

$(x+y)+z=x+(y+z)$