Answer:
B
Step-by-step explanation:
Given a quadratic equation in standard form
ax² + bx + c = 0 ( a ≠ 0 )
Then the discriminant is
Δ = b² - 4ac
• If b² - 4ac > 0 then 2 real irrational roots
• If b² - 4ac > 0 and a perfect square then 2 real rational roots
• If b² - 4ac = 0 then 1 real double root
• If b² - 4ac < 0 then 2 complex roots
Given
x² + 3x - 7 = 0 ← in standard form
with a = 1, b = 3, c = - 7 , then
b² - 4ac
= 3² - (4 × 1 × - 7) = 9 + 28 = 37
Since b² - 4ac > 0 then 2 real irrational roots
Answer:
10x5days+5=55
55÷14.25
=50.35
Step-by-step explanation:
Amanda earn $50.35. Amanda's wage is $50.35
Answer:
6. (a-4)(a+9)
7. (3p+4)(p-2)
8. Will explain below.
9. (5b+4)(5b-4)
Step-by-step explanation:
HELLOOO IM BACK
6. -4*9 = -36 (the variable), 9-4 = 5 (a) , so a^2 +5a - 36 is fulfilled.
7. 4*-2 = -8, 4-2 = 2, so 3p^2 - 2p - 8 is fulfilled.
9. 25b^2 = (5b)^2
16 = 4^2
Using the difference of squares formula, a^2-b^2= (a+b)(a-b)
Answer: 9 rolls of cloth A and 44 roles of cloth B
Step-by-step explanation:
Let x represent the number of rolls of cloth A that can be dyed and dried.
Let y represent the number of rolls of cloth B that can be dyed and dried.
A roll of Cloth A requires 50 minutes of dyeing time. A roll of Cloth B requires 55 minutes of dyeing time. The production division allocates 2280 minutes of dyeing time. This means that
50x + 55y = 2880- - - - - - - -1
A roll of Cloth A requires 45 minutes of drying time. A roll of Cloth B requires 30 minutes of drying time. The production division allocates 1740 minutes of drying time. This means that
45x + 30y = 1740- - - - - - - -2
Multiplying equation 1 by 45 and equation 2 by 50, it becomes
2250x + 2475y = 129600
2250x + 1500y = 87000
Subtracting, it becomes
975y = 42600
y = 42600/975
y = 44
Substituting y = 44 into equation 1, it becomes
50x + 55 × 44 = 2880
50x + 2420 = 2880
50x = 2880 - 2420
50x = 460
x = 460/50
x = 9