The sum of three times a number and a second number is five. two times the first number added to the second number is 10. find t
1 answer:
Answer:
-5 , 20
Step-by-step explanation:
<h3>Forming system of linear equations and solving:</h3>Let x and y be the first and second number respectively.
3x + y = 5 -------------(i)
y = 5 - 3x
2x + y = 10 -------------(ii)
Method used for solving: substitution method.
Substitute y = 5 - 3x in equation (ii)
2x + 5 - 3x = 10
2x - 3x + 5 = 10
Combine like terms,
-x + 5 = 10
Subtract 5 from both sides,
-x = 10 - 5
-x = 5
Multiply the entire equation by (-1)
y = 5 - 3*(-5)
= 5 + 15
You might be interested in
Answer:
15°.
Step-by-step explanation:
1. Angles ADC and CDB are supplementary, thus
m∠ADC+m∠CDB=180°.
Since m∠ADC=115°, you have that m∠CDB=180°-115°=65°.
2. Triangle BCD is isosceles triangle, because it has two congruent sides CB and CD. The base of this triangle is segment BD. Angles that are adjacent to the base of isosceles triangle are congruent, then
m∠CDB=m∠CBD=65°.
The sum of the measures of interior angles of triangle is 180°, therefore,
m∠CDB+m∠CBD+m∠BCD=180° and
m∠BCD=180°-65°-65°=50°.
3. Triangle ABC is isosceles, with base BC. Then
m∠ABC=m∠ACB.
From the previous you have that m∠ABC=65° (angle ABC is exactly angle CBD). So
m∠ACB=65°.
4. Angles BCD and DCA together form angle ACB. This gives you
m∠ACB=m∠ACD+m∠BCD,
m∠ACD=65°-50°=15°.
Have a good Day!
