Question

Given: m∠1=m∠2 and m∠2=75
Prove: m∠1=75
Statement Reason
m∠1=m∠2
m∠2=75


m∠1=75

Answer 1

How about due to the "Friggin OBVIOUS" Theorem

Answer 2

i get that, i just have to prove it i dont know the terms and such.

Answer 3

ive always been terrible at proofs haha

Answer 4

A = B
B = C
Therefore, A = C due to transitivity.

Answer 5

I can't believe they still make students go through stupid stuff like this.
Really makes kids hate math.

To be technical, I suppose you could say the reason is the
Transitive Property of Equality
http://www.mathwords.com/t/transitive_property.htm

Answer 6

thanks, i have a couple more if you/re willing to help. these things are screwing my grades up because i can do the problems i just cant do these dumb proofs

Answer 7

@BangkokGarrett i have to list reasons for all three things listed would the first be given?

Answer 8

Given
Given
Law of Transitivity (different teachers might have slightly different names.)

Answer 9

thanks a ton! how about this one? Given: x + 9 = 13
Prove: x = 4
Statement Reason
x+9=13
x=4

Answer 10

this one needs 2 reasons. sorry for taking your time these things just ruin this class or me and i need to do them to pass and theres 7 of them haha

Answer 11

x + 9 = 13 (given)
x = 4 (subtractive property of inequality. 9 is being subtracted from both sides of the equation)

Answer 12

Given: 2x + y = 70; y = 3x
Prove: 2x + 3x = 70
Statement Reason
2x+y=70; y = 3x
2x+3x=70

Answer 13

thanks @ranga ! if you could help me with a couple more that would be awesome

Answer 14

2x+y=70; y = 3x (given)
2x+3x=70 (substitution property)

Please see this link and choose the appropriate property:
http://www.basic-mathematics.com/properties-of-equality.html

Answer 15

Given: ∠A≅∠B
Prove: ∠B≅∠A
Statement Reason
∠A≅∠B
∠B≅∠A
@ranga is this the transistive or substitution property?or neither/

Answer 16

Symmetric Property. See the second item in the link I posted.

Answer 17

will do

Answer 18

i read through it i just dont know what iid put for one about a line segment
Given: XY is a segment
Prove: XY≅XY
Statement Reason
XY is a segment given
XY≅XY

Answer 19

@ranga

Answer 20

these are all just kind of confusing theres 3 left and im done with proofs for the semester/

Answer 21

The very first item in the link.

Answer 22

Reflexive Property.

Answer 23

Given:15y + 7 = 12 – 20y
Prove: y = 1/7
Statement Reason
15y+7=12-20y
35y+7=12
35y=5
y= 1/7

Answer 24

this has 4 reasons

Answer 25

last one, three reasons thanks a ton you're saving my tail
Given: m∠1+m∠2=100 and m∠1=80
Prove: m∠2=20
Statement Reason
m∠1+m∠2=100
m∠1=80

80+ m∠2=100
m∠2=20

Answer 26

Statement Reason
15y+7=12-20y Given
35y+7=12 Addition Property
35y=5 Subtraction Property
y= 1/7 Division Property

Answer 27

Statement Reason
m∠1+m∠2=100 Given
m∠1=80 Given
80+ m∠2=100 Substitution Property
m∠2=20 Subtraction Property