Answer:
25
Step-by-step explanation:
The pattern is + 1, + 3, + 6,... i.e. + 1, + (1 + 2), + (1 + 2 + 3),...
.'. Missing number = 15 + (1 + 2 + 3 + 4) = 25.
Answer:
tons of high steel and
tons of low steel
Step-by-step explanation:
Let x be the number of tons of high grade steel and y be the number of tons ow low grade steel needed.
In x tons of high grade steel there are
tons of iron
tons of magnese
In y tons of low grade steel there are
tons of iron
tons of magnese
NASA orders 500 tons of steel, so

and specifies that it must be in the proportion 80% iron and 20% magnese, so

From the first equation,

Substitute it into the second equation:

Answer:
Hello your question is incomplete attached below is the complete question
Given: wxyz is a parallelogram, zx ≅ wy prove: wxyz is a rectangle what is the missing reason in step 7? a. triangle angle sum theorem. b. quadrilateral angle sum theorem. c. definition of complementary. d. consecutive ∠s in a ▱ are supplementary. 1. wxyz is a ▱; zx ≅ wy 1. given 2. zy ≅ wx 2. opp. sides of ▱ are ≅ 3. yx ≅ yx 3. reflexive 4. △zyx ≅ △wxy 4. sss ≅ thm. 5. ∠zyx ≅ ∠wxy 5. cpctc 6. m∠zyx ≅ m∠wxy 6. def. of ≅ 7. m∠zyx + m∠wxy = 180° 7. ? 8. m∠zyx + m∠zyx = 180° 8. substitution 9. 2(m∠zyx) = 180° 9. simplification 10. m∠zyx = 90° 10. div. prop. of equality 11. wxyz is a rectangle 11. rectangle ∠ thm.
answer: consecutive angles of any parallelogram are supplementary
Step-by-step explanation:
The missing reason in step 7 is : consecutive angles of any parallelogram are supplementary i.e. m∠ZYX + m∠WXY = 180°
<u>Reason </u>: ZY || WX also XY is the transversal line hence ∠wyx and ∠wxy are the consecutive angles on lines ZY and WX therefore m∠ZYX + m∠WXY = 180° ( sum of consecutive angles )