Answer:
B. Montains / D. Desertes
Explanation:
maaf ya kalo jawaban nya salah"
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1. x(x+3) = x²+3x
Step by Step:
Apply the Distributive law: (a=x, b=x, c=3)
= xx + x × 3
= xx + 3x
= xx = x²
= x²+3x
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2. 3x(4x-7) = 12x²-21x
Step by Step:
Apply the Distributive law: a(b-c) = ab - ac
(a=3x, b=4x, c=7)
= 3x × 4x - 3x × 7
= 3 × 4xx - 3 × 7x
= 12x² - 21x
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3. -5x(6x-2) = -30x²+10x
Step by Step:
Apply the Distributive law: a(b-c) = ab - ac
(a = -5x, b = 6x, c = 2)
= -5x × 6x - (-5x) × 2
Apply minus - plus rule: -(-a) = a
= -5x × 6xx + 5 × 2x
= -30x² + 10x
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1. x(x+3) = x²+3x
2. 3x(4x-7) = 12x²-21x
3. -5x(6x-2) = -30x² + 10x
C: depositing silt, which created rich soul for growing crops.
Secondary reinforcers are learned or conditioned. An example of a secondary reinforcer is grades or money. Secondary reinforcers are learned and are reinforced by the continual use of the reinforcer. Primary reinforcers are biological and include food, drink, and pleasurable activities.